Google needs this tablet to defend Android. The arrival of Amazon's Kindle Fire blew a hole in the ecosystem, with Amazon setting up its own app store and its own look and feel for Android itself. If this 7-inch tablet is a hit, Google can argue that developers should still build tablet apps to Google's specs, not Amazon's.
When will we see it? The Google I/O developer conference on June 25 in San Francisco would be an ideal time to unveil it and maybe hand a few out to developers.
What does it mean for Apple? My take is that it means very little. If Apple's iPad sales were going to get hurt by 7-inch tablet sales, the Kindle Fire would have done it already. Apple is aiming at the higher-end tablet customer, who so far seems to be the larger and more profitable group of consumers.
It's just as likely as not that a 7-inch Google tablet will actually help Apple. While there will be plenty of confusing options at the low end of the market, with the Kindle Fire, Barnes & Noble's Nook, BlackBerry's PlayBook and now the Google device, there's just one strong tablet at the higher end: the iPad.
And don't forget: Apple is sure to unveil new iPad features with iOS 6 at its Worldwide Developers Conference in three weeks. That will make the tablet competition even more interesting.