Unfortunately, most of the XDA-devs forum deals with mainly GSM phones with users based all over the world (it at least appears to me that US posters is almost a minority on this site).
CDMA devices (Sprint, VZ, Alltel, etc) are huge in the US, but not as popular over seas. In fact, when the Sprint Mogul (6800/titan) was released, XDA originally did not want to make a section for it, claiming that the phone would not be popular enough to discuss amongst other forum members. I joined a group of people who petitioned the moderators to add a section, and clearly they eventually did. However, CDMA devices are discussed at length over at a similiar forum, www.ppcgeeks.com
Personally, I think XDA is a larger and more knowledgable community, so its really a shame that more of the developments aren't happening here. There are a few really good devs that have made the move here (such as DCD, his work is fantastic), and more and more people are finding that they prefer the moderation of XDA over PPCgeeks, but the fact still remains that more development happens over there. For example the "official" kitchens for the CDMA phones are released over there. You'll find many more ROM options (some good, some bad) as well as tutorials and details of the flashing process.
I personally try to be actively involved in both forums. Its the only way to stay on top of the state of the art.