"This offer is only available through this "secret link". There is a test :-) - the process to get to order is not as simple as we would like it to be, but hey, you are saving a $300 dollars (via rebate): Select "Save on the latest devices from T-Mobile" in the next page select "Click Here for Discounts" then "View Products" and last "Handhelds and PDAs" The $49.99 is only for new activations, does not include activation fee, and only requires a one year commitment, which is pretty good. The better news is that you will be able to upgrade it to Windows Mobile 6 via a sofwtare download soon." 
Even though I don't own one, I got to play with one for a few days. I really liked the Dash. You Dash owners are lucky and if you don't have one here is a shot at it pretty cheap! You have to jump through a couple hoops, so start jumping!