Problem is that they wont.

People still think more with their pockets. Even more because they can not grasp the difference between a new OS and some company finally letting you use the BT module that was inside of your phone for a "small price".

People think it is a nice idea to pay a bit more and get an "upgraded" machine because they are thinking that they made a GREAT deal. Heck, if Nokia would charge me 10e for M6 on my N900 I would sign up tomorrow. :P

I am deviating from the main topic of the thread now and talking more about psychology than about the technology under M6 and N900 but since there are a lot Nokia folks here, Hi Quim!! , maybe, just maybe, something might change...

Interesting thread, but I've only managed to read half of it. All the other software and library versions aside (most of it is OSS, it can ported from and to pretty much everything) the key point in being able to support older hardware in a newer OS is the availability of drivers for the hardware. If the kernel boots on the hardware, the rest is basically details. So the question I have is whether the hardware of the N900 will be supported by Maemo 6 (noone can answer this one), or better, is the hardware of the N900 supported by the kind of drivers which are portable to newer kernel versions. If the drivers for the N900 are binary only and Nokia won't update them to Maemo 6 then basically the N900 is a dead end.

OTOH, I'm sure the entire software stack of Maemo 6 will likely work just as well on the older kernel revision of Maemo 5. I care more about community support and updates than the "official" ones. Is there any deeply technical reason why the software stack of Maemo 6 wouldn't run on a Maemo 5 kernel which has the proper hardware drivers available?

So far the biggest potential hurdle is the input hardware (and thus likely usage paradigm), Maemo 6 being multitouch.

Even that should be easy to overcome by just having an option to switch it off, no? I cannot really imagine a usage paradigm that would be so dependent on multitouch as to render it unusable/non-user-friendly if turned off.

Neither can I. Games could use the hard keyboard. Things like pinch zoom, just zoom with rocker at the top. Or swirl to zoom. There probably is something that can be done only with multitouch but I can't imagine multitouch being enough a reason to block putting maemo6 on the N900.

If a lot of the apps that come with M6 are dependent on multitouch, you could stick with the ones currently in M5 that are not multitouch-oriented. Otherwise, a refresh of everything else may be nice, so it'd be nice if N900 users could upgrade to M6 for everything except the multitouch apps.

For re-binding to solve the multitouch problem, you could make it so you could hold down the volume button or shift key or whatnot while tapping the screen, and then release to create an "anchor point". Then, you could touch the screen again for the secondary point. Or, a key which toggles symmetrical pinching in which if you touch the right side of the screen, a mirror touch point is created symmetrically on the left side, making it pinch or zoom depending on if you moved towards or away from the center. I mean, most or all of the apps are going to be doing something like that any way, where the touch points are symmetrical in regard to the center of the screen. I can think of few instances where this won't be true. There's simply not enough screen space really to allow anything but that.

maemo is ****ing awesome. who needs gimmicky pinching touch? oh yea....

Correct me if I'm wrong but isn't single touch a subset of multitouch? If Maemo 6 will support multitouch it must also support single touch, right? So using a single touch hardware like the N900 means that the screen will only return single touch gestures, but that should not affect 99 percent of usability.

I agree with your conclusion (I can't believe that the interface must require multiouch); but your logic doesn't "prove" anything, in fact the exact opposite.

Have you seen Superman 3? There's a scene in a bank where Richard Pryor has to insert two key cards simultaneously, 6 feet apart.

Now, let's reread your logic:

A naysayer is me!
I don't think nokia will bother to port maemo 6 to the n900 unless it can be done in 20 minutes.
Think about it: why would they spend time and resources reducing their potential market for the next device? (i guess few n900 owners would buy the next one if they can have maemo6 without)
Then again, hackers have also done amazing things until now. Maybe there might be a M6HE