The only people who are determinded that Pit is nothing like YL are the people who don't like YL. Compare Pit to normal Link. Pit has a bow, has sword, similar smashes, he's a bit smaller, lighter, probably less powerful than Link. All just like YL. The only difference is the lack of bombs, and a different recovery. I'd say Pit's up-B is much better for recovery, but not good as an attack as YL's was. So it kinda evens out. So yeah, I'd agree that he is very similar and IF there is no YL, I'd assume Pit would be the best alternative so as to stick with the same style of play as YL.
As for being his replacement, I'm still hoping either YL or WWL will be in Brawl, so I wouldn't say he's a replacement just yet. He is his own character, so it wasn't for the sake of putting a new face on an old play style, I think they would have put Pit in the game with YL returning or not, but I still think he's your best bet to playing like you did with YL if he doesn't return.