Google today announced their much anticpated phone. They are calling it a super phone, with an impressive Qualcomm QSD 8250 1 GHz. Other specs include 3.7-inch (diagonal) widescreen WVGA AMOLED touchscreen, aGPS, Wi-Fi (802.11b/g/n), Digital compass, Accelerometer. Full specs on the google site
here.
Price is $529.00 for an unlocked phone that will recognize SIM cards from any mobile service provider using the GSM standard, but is incompatible with the frequency band used by the AT&T and Rogers networks for 3G data. Additionally, the Nexus One is incompatible with CDMA networks such as Verizon and Sprint.
For $179 you can get the Nexus One Phone with T-Mobile Even More individual 500 Plan. You must be eligible for service and accept a new two year contract to qualify for this pricing
It's due in Europe in the spring on Vodafone.

This is what Google says differentiates their phone:
The Nexus One runs on Android 2.1, a version of the platform's Eclair software. It offers the following features:
Speed
Snapdragon processor capable of speeds up to 1GHz
Voice-enabled keyboard and commands
Voice-enabled keyboard for all text fields: speak a text message, instant message, or complete an email
Voice commands: search Google, call contacts, or get driving directions by speaking into your phone
Use voice shortcuts in noisy environments with an additional mic allowing for active noise cancellation
Personalization
Dynamic, interactive, live wallpapers react to the touch of a finger
More widgets and 5 home screen panels allow for further device customization
Camera-quality pictures and video
5 megapixel camera includes LED flash, auto focus, zoom, white balance and color effects
View pictures and Picasa Web Albums in the 3D Gallery
Record Hi-Res MPEG4 video and upload to YouTube in one click
Read your voicemail
Get transcribed voicemail with Google Voice integration, without changing your number