I did an upgrade & contract extension this morning from a Sidekick; I don't see how adding a "feature" would bar them from selling a unit to you. Someone else just posted the outright price w/o signing a contract to be $429.
Got mine here in Minneapolis, MN. They can do upgrades and new, although the guy had to dig to find the upgrade pricing. $399 on the 2 year before a $50 rebate, and should have another $50 rebate from the T-Mobile Platinum Rewards program as well. Release the hounds!!!
You can do upgrades now, it all depends on the dealer if they would sell it just for an upgrade due to the fact that most stores have only a limited supply of these handsets and we would prefer selling it with an activation.
Search some of the other forums. They are doing upgrades for as low as $179 with a two year contract extension. Haggle enough, and threaten to move service (if out of contract) and it can be yours for not so much.