Google's not sharing hardware specs, but we're told Google TV devices will have WiFi, HDMI, the Intel CE4100 processor, and... some will have an IR blaster to tune your cable or satellite box, which is just sad. (Like, 1997 sad.) The input devices will all have keyboards, and you'll also be able to use Android devices as a remote, including using voice search to find content and sending content from the phone to the TV. The software is based on Android with Chrome as the browser and full Flash 10.1 support. Since it's Android, there's a version of Android Market -- any app that doesn't require phone hardware can run on Google TV. There will also be a Google TV-specific Android SDK launching in "early" 2011, along with the Android Market for Google TV.
As for partners, it's just as we heard: Sony will launch Sony Internet TVs and Blu-ray players with Google TV in the fall, and Logitech will introduce a set-top box with a Harmony remote and an HD camera for video chat at some point in the future. Dish Network will also launch a Google TV box at some point, while Best Buy will promote the platform as a whole in-store.
Make sure to keep up with the latest from I/O in our liveblog!