Gurren Lagann celebrated its fifth anniversary in 2012, but the celebrations aren't really kicking off in earnest until 2013. A rebroadcast is slated for January, and a big announcement is promised to run during the anime's new airing. Speculation is that this is going to be a new Blu-ray set, and early listings seem to offer some details on those plans.
Listings have a complete set selling on June 26th for 63,000yen ($730)
rebroadcast tribute from 音速犬