The problem with providing monetisation in App Mgr (or downloads.m.o, or packages.m.o), say via PayPal is the technical restrictions to prevent piracy.

Nothing too invasive, but you want to prevent anything rampant. Would it be enough to just provide a one-time use install link? A "XB-Requires-Payment: 0.99" header in the package (you then have a daemon which prompts the user for payment after 14 days for any packages)?[1] Do users like to pay for the apps on their desktop? Download them there too?

The big initial attraction for developers to the iPhone were, IMHO:

• A compelling user experience: it was a nice device to use as an everyday tool, so they then could scratch-their-own itches.
• Very powerful debugging and development environments which were simple to set up.
• A compelling user experience which gave them a high bar to aim for, and an easy route to getting those same experiences from their own apps.

See also http://www.youtube.com/watch?v=eCGTZ-1LGRw and http://www.youtube.com/watch?v=J715B63ddfY

That set up a self-feeding circle which got more users, developers and applications - so money and micropayments do seem to be the primary factors now.

I don't know if the same factors will be repeatable now for a relatively "new" platform; which is also competing on the same ground, for similar mindshare and developers with Android and webOS. I suppose we'll see... :-/

[1] Hmm, I seem to have come up with a monetisation/donation system which could make me money without any changes or modification by Nokia. All I'd have to do was to ship this payment daemon; applications which want payment then depend on it and I take a cut of the proceeds. Relatively trivial to circumvent for an advanced user, but for the everyday user, it might make some cash. Anyone want to help? ;-)