They all support GPS for the purposes of E911, but I don't think most of the phones that triangulate position from tower data support GPS for application developers or anything other than E911. http://electronics.howstuffworks.com/gps-phone2.htm

It doesn't matter whether they do or don't. The problem with GPS receivers is that they do not work reliably indoors. If Loopt relies entirely on GPS to locate users then this offering from Google is superior.

Nearly all CDMA phones sold in the US today support Mobile based and assisted fixes from applications.