Well, the guys in this forum, as well as another site are reporting manual transmissions available in all levels in 2009.
The SRT8 and R/T will have Tremec 6 speeds available with slightly different gear ratios between them (3.92 in the SRT8 and 3.73 in the R/T, 3.06 and 2.82 respectively in the 5 speed autosticks). They also report a 4 speed automatic behind a V6 in the entry level Challengers.
The 5.7L HEMI in the R/T is very strong. But if you're a "power hog", you wouldn't be satisfied knowing a 6.1L was available in the SRT8.
There have been rhumors that the 6.4L motor (510 hp) "may" be available at some point in the SRT8, but most of us doubt that. Too bad.... that'd be an awesome powerplant and very hard to beat.