From AICN HERE:

Original Film On Blu-Ray
One of our readers, Guido Anselm, sent the following in after beholding the new TRON LEGACY trailer at last weekend's premiere events. Sounds like early indications of the original film being issued on Blu-Ray circa LEGACY's debut are...not surprisingly...correct.
Guido was able to glean a few more details about its issuance by virtue of his placement in one particular theater - where original TRON overlord Steven Lisberger (also a writer/producer on the new film) was in attendance.
It turns out my buddy and I were sitting
right in front of Lisberger and we overheard him talking about how he
just finished over-seeing complete color-correction and major
enhancements to the original TRON for BLU RAY! It sounded like he
basically kept the movie the same (no CGI inserted) but corrected the
colors throughout the entire film and enhanced everything. He said it
was a dream to go back to something he made thirty years ago and
correct it to look exactly how he would want it for the Blu Ray
release (which he made no mention of when that would happen). Anyway,
Lisberger never mentioned any of that in the Q and A and I thought you
guys would want to know about it.