I don't know what you guys are talking about. Angry Birds on my N900 often slows down, pauses, jumps, jitters etc.

Maybe it's because in the background it's also running several instances of micro-b, downloading updates, running Doom (prboom), Duke Nukem, Wormux, Bounce Evolution, playing some music whilst showing me the lyrics, scrolling my friends' facebook status updates, giving me live update of the London Underground lines, showing me a teletext feed and running google maps, all whilst bluetoothing some files to my friends directly from a network share on my home server...

...at which point any iPhone waving friends have slipped their phone back into their pocket and sat down quietly in the corner.