It's a cross between Pandora and iTunes, but it's waaaay better than Pandora/Grooveshark/etc. It's hard to explain, but once you try it, you love it.

This is what worries me.

I don't like because who is to say you won't just download every song known to man in one month for just $10? All the music in the world, of all time, is worth more than that?

Besides, 10 x 12 = 120, which is not far from what I pay on iTunes every year for new music.

It would be a great move. I love Spotify. I'm listening to some awesome stuff I've just found out right now
I wouldn't afford them all if I buy them on iTunes.

The iCloud storage is already in place so I don't see why some sort of change wouldn't come with iTunes. But not soon. I'm sure Apple is watching these 'music streaming services' and waiting to see the outcome

No, but with the paid subscription you can listen to unlimited music on any iDevice

If they did that it would really be a cross between Spotify and iTunes, and it would be serious competition. They don't sell the music like that, they just make it available for you to listen to anywhere.

Spotify is not even available worldwide yet and look at the numbers It would be MASSIVE if it was.

January, 2010:------------ 250,000 paid subscribers
March 17, 2010:----------- 320,000
July 20, 2010: ---------------- 500,000
December 8, 2010: ------ 750,000
March 8, 2011:--------------- 1,000,000
July 14, 2011: -----------------1,600,000
Sept 21, 2011: ---------------- 2,000,000
Nov 23, 2011: ------------------2,500,000 paid subscribers

my guess

Feb 2012: --------------------3,000,000 paid subscribers
July 2012: --------------------3,500,000 paid subscribers
Jan 2013:----------------------4,000,000 paid subscribers (I'm pretty confident that 12 months from now, Spotify will surpass 4 million subscribers)

The goal:
10 million subscribers = $1,200,000,000 annual revenue.