Well for starters- "open source" that's not open source.
It will only get ICS when the Asus gods gift it to us, no hunting and gathering for us- which also may become an issue when they stop support for it and move on to the next product.
But mostly the open source thing. That's the whole freaking point for me really- I don't particularly want to support Apple with my purchases and they are pretty much the only other manufacturer to look at. I think they have great products but I don't like the locked cage thing they have going.
So at the moment I am running a Gigabyte hybrid laptop for my portable while I wait for someone to make a product in the Tablet category that has what I want. The Asus Transformer Prime was looking good, but now they've locked it they're just as bad as all the rest.
If they are going to lock "Open Source" then we might as well stop calling it Android and start calling it Windows.