I saw the trailer and it looks ok. He looks younger than he really is.
On another note, the internet is fucking stupid. Everyone on the internet thinks they are some intelligent critic, and everything apparently SUCKS. Nothing is good, or merely adequate. Everything that is remotely unlikable, has to suck donkey balls.
Fuck you internet. Transformers was an entertaining movie, Shia is a pretty good young actor -- you may be confusing him with Hayden Christiansen, Bioshock may have taken heavy inspiration from System Shock 2, but was still a good game, and this Indy 4 movie looks pretty decent.