According to TreoCentral some customers have reported success in ordering Treo 650s from Sprint PCS. Delivery dates are as early as tomorrow, meaning the units have already been shipped.
However, Sprint isn't giving tracking numbers, so the reports cannot be verified. If you want to try your luck and you are already a Sprint PCS customer (this method only works for existing customers), call (866) 343-1114.
Sprint PCS has an exclusive for the Treo 650 through 2004. Most other carriers are expected to pick of the 650 sometime in the first half of 2005.