Guys please, PM has nothing illegal or it would have been shut down ages ago. The only circumstance it would be illegal is if was being sold. It is still of Nintendo's right to ask for its development activities to be halted, but not for being illegal, but for using their IPs and they having power over them.
It's also illegal if you are playing it with a Brawl iso while not owning a copy of the game, but just for you since you are pirating the game. In that case even your brawl is illegal.
Also you might be overestimating the reach of this community to believe that PM might represent any kind of threat to Smash 4's publicity. It is a popular mod, but only in a very specific demographic and it's all it aims to be, the total public of Smash Bros. is much bigger.