The rumored t739 Katalyst from Samsung has gotten official today for T-Mobile, shoring up a Hotspot @Home lineup that presently features the lowly Nokia 6086 down in the basement and the BlackBerry Curve 8320 up top. The t739 is the first slider certified for T-Mobile's WiFi-enabled calling service, giving it an instant dose of street cred among folks that love the UMA concept but can't stand clamshells. In fact, with a 1.3 megapixel camera, Bluetooth, and a 220 x 176 display, the Katalyst is essentially a slider rendition of the t409 with the addition of a microSD slot. Yeah, we'd still like to see a little more meat in the lineup -- a 3.2 megapixel camera and 3G would get us to shut up, just as a fr'instance -- but in the meantime, we're always happy for a little choice of form factor. Grab it for a penny shy of $80 on a two-year contract.