Mysterious Google mobile event on Thursday

It appears that Google is getting ready to announce a couple new features for Android on Thursday at an invite-only event, according to an invitation received by Gizmodo. There is only speculation at this point about what might be announced, but whatever it is, events like this tend to generate lots of buzz, and high expectations.

There are a few things I can think of that may come up Thursday -- my best guess is maybe the new Android Marketplace (with music, and a full web-based version of the market) is ready for prime time. Other guesses include a sneak peek of Gingerbread, or perhaps something completely different. Last time an event like this took place, Google's Navigation app for Android was announced.

Curiously, it appears that the launch for Motorola's next phone (Droid 2) is on the exact same day. Since it sounds like there are going to be "features" demonstrated, I don't think it's going to be specifically around Droid 2, but you never know I guess.

What is your best guess?