Although I too am a hardcore OT fan, the only SE changes that I'd like to see are minor improvements that simply clean up the old effects: erasing matte lines, removing those "boxes" around the TIE fighters and other ships, erasing the blob under Luke's landspeeder, fixing Obi-wan's lightsaber in that one shot where it looks like it's running out of batteries (anyone else notice this?), etc. I would have even fewer changes in "Empire" and "Jedi", since those were obviously a bit more polished than "A New Hope" when they first premiered in '80 and '83, respectively.

Other than that, leave everything as it is!

No new scenes, new CGI, etc. If Lucas is really that unhappy with the original films, he should simply remake them from scratch. It's been 27 years, after all.