And I'm not talking about the guys that are just taking apart to see what's inside of it, I'm talking about the guys that are playing with the actual software to try and make it do more things.
In near-real-time I'm watching a conversation between people on a board talking about how Apple may have disabled USB keyboard support and how they might be able to use standard OSX software to fix it. This thread started off with figuring out how to get the AppleTV to play other formats, which became the gateway to enabling other functionality.
5 years ago this wouldn't have happened easily; 2 years ago this wouldn't have happend this quickly.
Link (I'm linking to the last page in the thread at the time of writing this post)
Oh, and people have already figured out how to upgrade the hard drive (I'm guessing you pop out the factory one, put it in an external housing, and use Carbon Copy Cloner to transfer the software to a bigger drive).
Oh, and people have figured out that a widescreen tv is not necessary; any tv with component video inputs seems to work to some degree.