I'm in the UK so only just read about this a couple of hours ago, I immediately contacted one of my best friends who is a manager at EMI in London, in the Digital Development Dept. asking him if he has heard anything on the 'inside'.
As far as he is aware, as far as Apple is concerned (not including Spotify, as this is a different service all together) it's too soon for streaming music under a monthly subscription, because no contracts have been signed yet between music labels, publishers and Apple themselves. Under the current contracts EMI has with Apple, none of these cater for streaming because apparently this comes under a different "tarriff" - none of which have been agreed yet.
He said not to rule it out for it still being the announcement, because Apple can still of course use certain labels they do have permission for, but for a launch - EMI is a pretty damn big label to miss off the starting lineup.
I wouldn't get your hopes up regarding cloud based streaming subscriptions juuust yet, it will come soon enough.
Facebook integration is an obvious direction to go in, even iPhoto '11 has excellent Facebook integration already, it would be a no brainer.
I'm going to edge my bets on wireless sync with iOS4.2 and iTunes, and iOS backups to be saved on the cloud.
Along with new gen

TV update to include PURCHASES which can be stored on the cloud; each individual iTunes account holder will be given a certain amount of storage (more GB for extra £$) a la Dropbox and content will effectively be streamed to your

TV from there, rather than the HD on your iMac or Macbook. (it always seemed ridiculous to have to leave your computer on with the new

TV, when you didn't have to with the old gen...they must have plans for this to change)
Thoughts?