If I'm filming I'm not interested in getting new email notices ... or IM messages. I want a good steady shot, no dropped frames, maybe even some help from the CPU in non-favorable light conditions.

If the hardware/software implementation is not powerful enough to do all at once, then I think things should be pragmatic.
I do think the Maemo ecosystem is too much desktop Linux driven, actually ahead of it's time, designed for devices with ample resources, allowing the walhalla of real-time multitasking at the expense of user experience and performance of the frontend tasks.

Lets hope Meego has better provisions for preserving User Experience and performance. But honestly, I think better HW is the only thing to keep all running as envisioned during design.