The iPAQ 6315 runs Windows Mobile 2003 Phone Edition, not Second Edition. HP would have to develop an upgrade and T-Mobile would then distribute it. Since the phone is so new, it's not likely we'd see this right away-- I'm hoping by December, but that's just a guess.
T-Mobile seems to have special data plans for the iPAQ. They're pricey compared to T-Mobile's $20/month Unlimited Internet GPRS plan, but they do include both GRPS and WiFi at T-Mobile Hotspots.
-------------------- Lisa Gade Editor in Chief, MobileTechReview