On the 20th Tmobile will release the MDA(AKA the Qtek 9100, HTC Wizard)
I too am looking for a Sidekick replacement and am considering the MDA.
Will have to wait till Monday for the details on the service plans. A rep in the store told me it would be $29.99 per month for the data service, txt msg not included and calls are $.20 per minute. I'm assuming it's the internet plan however when I check the web site at tmobile.com the Internet Plan is 44.99 per month and that's GPRS(not EDGE)
Will have to wait and see.