OK, I see this affecting different people somewhat differently:
hardcore internet geeks - they probably wouldn't do it, because downloading stuff is their thing
normal users - they probably wouldn't do it because they don't really care that much
also pirates - yeah right
I doubt it would be a massive success, maybe there would be a small decrease in online activity but I question whether it would be noticeable at all (would it deviate from normal highs and lows of internet usage).
And stop portraying Megaupload as the victim! Sure, maybe it was just a bit harsh to close it, but it's not like it lacked any illegal stuff. It was a pretty solid alternative to torrents for pirating.