This morning a tipster sent these images claiming to be of Trill (SCH-r520) and T401G. Trill was leaked last month and the details jibe with the previous report. Bound for US Cellular, the slider phone is targeted at music aficionados that has a dedicated music button, 1GB internal memory with microSD slot supporting up to 32GB and Bang & Olufsen ICEpower for rich audio quality.
T401G goes for the text messaging crowd with an alphanumeric keypad on the front and a slide-out QWERTY keyboard, 1.3MP camera and microSD card slot.
[Thanks, coolboy!]