There were two Brawl rumors posted about before: one was supposedly from a Spanish magazine and the other was supposedly an email about Brawl at the E for All Expo. The Spanish magazine one was a fake, and we now learn that so was the email. Here's a response from the guys at the E for All Expo:
You may have spotted a rumor making its way around the net about Super Smash Brothers Brawl at E for All. While we hope the rumors are true that Smash Brothers Brawl will be playable at E for All and that Masahiro Sakurai will be in attendance, Nintendo has not finalized their plans with us and we have no information confirming this. These are questions best answered by Nintendo at this point.
As far as the email that was found circulating the internet from a “Mark James”, we don’t employee anyone with that name.
I assure you that your interest in playing this title at E for All has not gone unnoticed.