Google officially announced the Nexus One. Check out the specs:

3.7-inch AMOLED touchscreen
Qualcomm QSD 8250 1GHz processor
Android 2.1 Operating System
512MB of Ram
5MP, 2x digital zoom, LED flash camera
Wi-Fi enabled
130 grams weight w/ battery
Complete lineup of specs available here.

The Nexus One is available unlocked for a price of $529. Consumers can also order the phone through T-Mobile for $179 with a two year contract. Verizon Wireless customers will also be able to purchase the phone later this spring. Europeans will also be able to purchase this phone through Vodafone later this spring as well.
More information is available on the Nexus One website