But wait, you just wrote it up there. Harmattan is Qt, with GTK/Hildon marked as deprecated (it's still there but don't build empires on it). How good/serious that community support will be is another issue. Quim said clearly they don't have the resources to maintain both in equal status. I'd go as far and say it would be downright silly to have both in a pretend-equal status, even for one release, when you know that one of those is going out the door (that's why you have the deprecation stuff in the first place).

I can see your point and in fact even agree that this is what should have happened in an ideal world.

OTOH: I am not yet certain about the quality of the "community supported" versions of Qt/GTK. If they are both rock solid, then you get what you want, don't you? At least wo releases in a row that feature both toolkits.
You may even get GTK-support long after Harmattan... Who says GTK is deprecated? If it's there in extras, it can as well be there to stay.

Pulling it in as a dependency may sound a nightmare on current hardware, but who knows how much memory we will have available on Harmattan devices?

So a lot depends on the quality of the "community supported" versions of both toolkits, especially on the quality of GTK in Harmattan and later versions. It can go all wrong... or it could be very easy. What I'd hope for is that one of the other players who currently seem to hesitantly watch Maemo grow (Intel? Ubuntu? ...?) find it interesting enough to get their hands dirty here. "Community supported" doesn't necessarily mean that members of this forum need to do it on a rainy weekend.

Well, no:

It all depends on someone picking up the ball and having sufficient time and skill to manage a decent port in time for the Harmattan release.

The only somewhat realistic development path for new apps (unless you want to support Diablo) is to go with Qt and hope any bugs you come across are not showstoppers. But if I was a commercial developer I would be dropping the platform for the next couple of years until they get their act together.

Then why no updates since 2007? Again... no compelling reason(s) based on prior experience to continue supporting these decisions that are based on... "logic".

There is no need rewrite whole application, only the UI part.
Re-engineering UI is mandatory issue if you are porting desktop
application and like to make your application mainsteream mobile
application. Do you think that iPhone applications are just made
by compiling Macintosh desktop applications without doing anything
to UI ?

If you would like mane modern up to date mobile UI you should
use either Qt or Clutter and that mens re-engineering the UI layer.
There was no choice not re-engineer but choice of what toolkit
to chose and Nokia chose Qt.

If application developer is not willing to design mobile UI then
application is doomed to be niche audience product.

This is not really my area of expertise, but AFAIK there's no easy way to bolt a Qt UI onto a pre-existing plain-C application. If there is I'll be more than happy to be corrected :-)

Well, generally I don't have strong feelings about using Qt or Gtk+ for new applications. But switching toolkits now will be very challenging for Maemo, the community and Nokia. Amongst others I see the following problems.

* Qt in Fremantle doesn't look like Gtk/Hildon in Fremantle. It looks much more like Gtk/Hildon in Diablo [1] [2]. So Fremantle will not be the right place to already start with Qt.

* Gtk/Hildon community support will (probably) suck. We (the community) are barely enough developers to produce great applications. No offense meant, but we have about 500 apps and many of them are simple ports or no longer maintained. Others are still young and developer time is mostly rare.
If you then look on how much time the Hildon/Gtk (full time) hacker are spending to get the code into shape for Fremantle, I don't see how the community can produce a Harmattan Hildon/Gtk which looks and feels good.
Maybe it will work that we'll have Fremantle-Level Hildon/Gtk support, but what about the new features and a new look of Harmattan?
If development is like it is now, then no one will even know how Harmattans Qt is exactly looking before the final release. How should the community come up with something that will integrate regarding look and feel?

* As I wrote earlier we are only few developers but still we have a couple of hundreds of applications to port. Now some people here write that you only have to rewrite the UI layer. Well, for some applications this might be true, but there are also apps that are heavily depending on Gtk. Porting those apps will basically mean rewriting. If I check Conboys code, I think I'll have to rewrite about 70% of the code. Probably it will be easier to start all over again. Now that's not really a good motivation. Especially it's not a good motivation for introducing new features into the Fremantle/Gtk version now.

* Write once run everywhere will also not work with Qt. Desktops and Phones are just too different, so porting the UI is still the same story as today with Desktop-Gtk and Hildon.

* Also it was mentioned that Gtk+ is obsolete and Clutter or Qt should be used anyways.
Well, first Clutter is no replacement for Gtk+ nor Qt. Second, Gnome 3.0 will still be based on Gtk+ and IMO it's not looking obsolete. And third (very personal) I don't see the need for animations and 3d effects when writing an email or doing a phone call. And animations like window switching have nothing to do with the toolkit.

* Last but not least, we loose the complete knowledge that was build up within the last years regarding C, Gtk+ and Hildon. I guess that also means loosing people...

I think for me personally the main problem will be motivation. I'm not really motivated anymore to put energy into a project that I can mostly throw away in a year or two. And I'm not motivated to switch to Qt now, because right now Qt pulls in a lot of dependencies and it doesn't look good on Fremantle.

Dilemma

Maybe beacause supporting a GTK based app is takes more resource for them as they are native QT based ?

Again, if they didn't support GTK app, they might also not support a QT based app either.
This is in no way related to Maemo moving from being GTK based to being QT based. Hopefully it will be the other way around - once Mameo is Qt based, Skype will have more frequent updates (at least on Par with the desktop linux version) .

That's because the world at large is still using the wrong tools for the job. If they used the right one, switching toolkits would be just a configuration option
(just partially kidding, it wouldn't work for the tablet).

I agree, but, hey, preteens love these things....

But welcome kopete, kword, kcalc, etc.

I suppose it will be much easier to make KDE apps running smoothly on Harmattan then port Hildon apps.

While there will be problem to replace apps created from the start as tablet tools (eg. seqretary, conboy) replacement of desktop-derived programs should be much simpler.