..where can I buy a smartphone for which the source of it's shipping firmware is actually available?

Any mobile system lacking J2ME is useless.

Symbian and Windows Mobile are dying because they can't give the multi-touch experience of iPhone and Android. Hopefully, the open-sourcing of Symbian will spur more development, and get it a swanky multi-touch interface.

At least Symbian still has over 50% of the worldwide smartphone market, so it has some space to improve (it can keep falling for a bit longer and still be very big).

Windows Mobile, on the other hand, has no hope for survival, as it has already fallen to just 9% of the market (it can't go much lower), it has no traction, and there's no hope of it ever being open-sourced. A rejected OS that Microsoft is still spending billions of dollars on, with little improvement to show.

I agree with the comments above that Android will become the dominant mobile operating system. I still hold out hope that Nokia's Maemo OS will grow into something big.

agreed that Android was a bit ahead of the Symbian Foundation, but then again, for how long?
Open Source is not synonym of open governance.
There is no visibility of Android's roadmap and Google is the only one controlling the OS.
Symbian tries to be as transparent as possible and is for now the only operating system that enables such a degree of visibility and involvement around the platform.

...while Symbian snoozed in closed-source mode.

I think that Symbian is now heading for the equivalent to Fortran in terms of applicability/ marketability on telecommunication devices. Android is going to take over now.

The ARM compiler for free?

Wonder what else this can be used for ?