The Samsung T659 or Scarlet as it's codenamed, will be heading to T-Mobile sometime in the future. Some of the features and specs are:
*quad-band
GSM support
*
3G 1700/2100MHz
* MP3 player
* Bluetooth
* 2MP camera
*microSD card slot.
Launch date has not been mentioned.
via:
Samsung T659 Scarlet slider pictured | Samsung Hub 