Blitzkrieg said
And you will still have the old StarWars you love even if they screw up, they can't erase history.
No, but they can try as hard as they can.
The 1997 VHS tapes had Greedo shooting first, irrevocably changing Han's character (hence the 'Han shot first!' cry from fans). This means that you can't actually find a good-quality version of Han being the sole shooter, as he was in the theatrical versions, the last version was the Laserdisk release.
Same for the 2012 BluRay version, Vader now screams 'NOOOOOOOOOOOOOOOOOO' as he throws Palpatine down the chute, irrevocably changing his character. While the angsty aggression suits the character that Hayden Christensen played, it doesn't fit with the Darth Vader that the original trilogy portrayed. With screen resolutions consistently increasing, soon the DVD versions will become too poor quality to show, leaving only Lucas' changed versions as the 'right' version.
Lucas quite easily fucks with history, so we have plenty of reason to bitch. If Lucas can do that just by re-releasing the original movies, how bad can Disney and JJ Abrams do while mucking around with a new trilogy of movies? I'm not sure I want to find out.