A couple of people at the TAF have already reported in on 2ch.
-Formal name is "Tengen Toppa Gurren Lagann Crimson Volume" (天元突破グレンラガン紅蓮編)
-This movie is Part 1
-The dubbing will all be newly recorded
-There will be new scenes
-It will open in theaters on September 6, 2008
-The theme song will be by Shouko Nakagawa again