Let the hive mind of Engadget get that for you.
"I've found myself using my PC for a lot of conversations lately, and I'm also considering recording a podcast to share with anyone who will listen. There are tons of USB headset / microphones out there, and I'm hoping someone has some solid recommendations based on experience. I'll consider both headsets and standalone mics, by the way, but I'd like to keep the bill under $100 if possible. Help!"
No current EVDO handsets are not compatible with any other revisions which is a real pain. Right now Sprint is working on getting EVDO Rev. A handsets to be released mid '07, which means to take advantage of Rev. A a user must upgrade his/her handset, once Rev. B comes out same thing and so on for any Revisions.
Are you sure about that? I figure there must be a way to prep a handset to be forward compatible. My Sprint Mogul was ROM flashable from EVDO Rev. 0 to Rev A. Worked like a charm. Or is this what you mean by "upgrade his/her handset?"
...then again I got my Mogul in early 2008 and your post is end of 2006. Well, they were only off by 6-12 months.