It's been awhile in the making with lots of false releases and half-fixes (Soft SPL anyone?), but at last the full Hard SPL is now available by the DarkForces Team (bepe and Cotulla) for the much coveted HD2 (see hands on and review)
(And yes, it should work on the U.S. T-Mobile version, but we'll have to actually wait for its release to verify)
Not much else to say except find your favorite chef and forum and start browsing for some custom goodness. As usual, be aware there is a risk with flashing a Hard SPL and using custom ROMs, so feel free to wait on the sidelines for 48 hours, m'kay?