Too melodramatic a title, I know.
T-Mobile has never had much of a Windows Mobile line-up to start with. They recently dropped the only Windows Mobile Pocket PC Phone Edition model they carried: The MDA. This leaves them with two Windows Mobile Smartphone models: The SDA and the Dash.
The most likely reason for dropping the model is because T-Mobile is getting ready to introduce a Windows Mobile 6 Pocket PC Phone Edition (now called Professional Edition) to their lineup. But, wouldn’t it be interesting if they were the first of the mobile carriers to drop the Pocket PC Phone Edition altogether. Ok, it is unlikely. But still, this is something that will happen in the next year or two IMHO.