"I couldn't see a way to create or otherwise use bookmarks from within the browser. "
Have you tried using the keyboard shortcuts from the PC browser? (I don't know if that works, but people are saying most of the keyboard shortcuts are the same)
"but Google can't let the same riotous sprawl hit living rooms that we've seen on its smartphone marketplace"
Its called 'choice' - if you want someone else to make the choices for you, you could always get Apple TV
"Perhaps this is why Google is waiting until next year to open up its TV app store and broaden its functionality."
No, here is why: Each version of Android has certain compatibility definitions manufacturers must follow if they want to be considered a fully compliant Android device.
They don't have to - but then they don't get access to the proprietary Google apps, like the market)
So, amusingly enough, according to Googles own guidelines, Google TV is not a compliant Android device (for instance, version 2.1 of Android requires the device to have GPS - obviously Google TV doesn't have a GPS nor need one) - so instead of giving themselves permission to break the rules (and risk lawsuits and angry manufacturers) they adhered to the rules and didn't add the market.
Now the next version of Android is very close, and there they can make sure to phrase the new rules for requirements in such a way that Google TV will be compliant. And since the new rules apply to everybody, nobody need get upset.