Yeah, I have my finger on Apple's pulse and I seem to be adept at getting into Steve's mind

My
futurecasting of AppleTV appears to be unfolding pretty accurately as well.
My analysis on the subject of a MobileMe cloud comes from my belief that Apple will use Me.com as a driver of sales for iTunes which will justify offering MobileMe for free. Streaming only purchased content will keep the labels and studios happy as it will not only discourage piracy but it will encourage more purchases of media content. This is probably the sales pitch Steve made to win them over and allow streaming of previously purchased content.
However, going only part of the way with people's libraries wouldn't be an attractive feature overall. People will want all of their content available, not just part. A good compromise -- one that doesn't require insane and frankly unsustainable storage on Apple servers -- is to enable iTunes via Me.com as a no setup, no complexity, no management streaming server of your other content.
Hopefully this is what is announced tomorrow.