As rumored last week, T-Mobile USA today launched the Samsung X495. The phone is an update to the X475 which is still for sale on T-Mobile's webstore.
Features of the Samsung X495 include:
T-Mobile is selling the X495 for $49.99 after an $80 instant-rebate. A new service contract is required.
Two other devices were rumored to be launching on T-Mobile soon, with the launch of the X495 these rumors probably have more credence.