@jgombos: Your "serial number" is just your MAC address. If you're *really* paranoid about them seeing it, I'll be happy to just email or pm you the EULA, but really... (or are you saying you don't have a tablet?)
Anyways, lots of stuff is actually closed source. Chunks of the media player, parts of the desktop, some home applets, some statusbar plugins (brightness and volume at least), wifi, dsp (sound...) and bluetooth drivers, as was mentioned before, probably quite a few userland programs, including the browser UI. It *is* disappointing. Some of us (including me) are trying to get Debian working nicely, but for now closed source stuff is needed for sound, bluetooth and wifi. It's not a terribly useful machine without that :/ And you realize most of Android has no source at all yet, right? It's binary only until Google decides to release their stuff...