The Bravo will be available for GSM networks. It might be available in a CDMA version, but that is not clear at the moment.
Also, the Bravo will have a screen resolution that isn't as high as the Nexus One. The other specs on the Bravo, though, are very similar to the Nexus One. The Bravo is coming out in April 2010 according to HTC's product roadmap.