I've been posting my speculations around and haven't seen similar opinions on this thread yet, so here it goes.
1. iPod Nano: internal wifi antenna
2. iPod Touch:
A. IR +/- RF and light sensor for expanded remote functions
B. Some hardware updates to make apps more cross-compatible (e.g., camera, crappy speaker/microphone; probably not GPS, just because they have no other source for maps than Google. On the other hand, a lot of the best apps include localization features, so who knows).
3. iTunes 8.0:
A. audio streaming to Nano
B. audio streaming to Touch (maybe video)
C. streaming functions over any network
D. music stream is tied to each individual user/PMP to collect behavioral data (music listening behavior) which are used to generate individual playlists and to suggest new music
E. sharing library with friends (just like Simplify Media's app)
I'm a little skeptical about Apple getting into the individualized music streaming business, just because it's a new business model involving paying streaming music royalties, which have caused so much trouble for Pandora Radio, internet radio, etc. However, maybe they'll ask you to buy a certain amount of music in exchange, just like those CD clubs where you got 12 CDs for one penny and then tried to scam your way out of the rest. But there's no doubt that that behavioral data connecting listeners to new music is valuable to an effort like the iTunes store. I just hope they push event information like LastFM does, instead of just pushing recordings. Living, performing artists benefit most from live performances, and a lot of people would like to know where to see live music, not just buy recordings. However, Apple and recording companies really only benefit from the sale of recordings, so who knows.
Anyway, my two cents.