HTC launched a kind of update to the Nexus One, named Desire. It's a very similar device, having the same capacitive touch-screen (3.7 inch), the same processor (Qualcomm Snapdragon at 1 GHz) and the same battery (1400 mAh). But what's weird is the difference between battery life on devices which is quite big.
HTC Desire also includes a 5 megapixel camera, which has face detection capability (I don't know if the 5 megapixel camera from Nexus has this option). Anyway, both devices have G-sensor, digital compass, proximity sensor and ambient light sensor. Desire has 576 MB RAM, while Nexus has 512 MB RAM (the difference is probably felt only on intensive tasks). Both devices runs Android 2.1 OS, but Desire also includes the Sense UI, which is not present at Nexus.
Nexus costs 529 $, but it is not available worldwide yet. Desire has been launched today, 16th February, and I didn't get an official price yet. If I found out a price, I will let you know.