I like the subscription (rental) model. I have been using it for nearly 2 years now in the Windows world.
The ability to pay $9.99 per month and have access to 2 million songs is far more valuable to me than paying 99c per track.
In the time I have subscribed I may have bought a couple of hundred songs, which I might typically get bored with quite quickly. Instead I have about 14,000 subscription songs that I can access so I do not get bored with the music and I am finding constant variety and new artists all the time. This is where subscription music excels the ability to explore new artists and genres without feeling that you are wasting money on a song of unknown quality (if you were to buy).
Do I own the music? No. I do not care. The way I look at it, to purchase 14,000 songs via itunes would cost around $14,000. I do not have that much to spend on music. However, even if I did, $14,000 would buy 116 years of subscription music at $10/ month - so I am not going to worry about the fact that I am paying per month for the right to listen to music.
Plus in 116 years - apart from being 6 feed under, I would have listened to a whole lot more that 14,000 songs.
I believe subscription has a future, I am surprised that people here are so hostile to it. The solution is simple. iTunes should offer two models for music delivery. Purchase and subscription.
People can purchase their music if they want (though I would only do it if it were lossless and DRM free) and others can subscribe - explore their music and still buy if they want. The two models models are not mutually exclusive.
I use Yahoo! for my subscriptions. Now Yahoo! kind of sucks but the subscription service is excellent with good quality 196kbps WMA tracks.
Do not bash what you do not know, until you have tried it.