Yeah, I did this too. Since i'm a new DM as well, and most of the players are new, I allowed them to adjust/fix their characters once before our next game.
After playing only once, they had a much better idea of what worked, what didn't work, and how their powers work.
Thing is, I told them they could only do this once since we can't be changing our characters around every game.
Even after this stage though, D&D does allow you to change a power/feat every level. So if someone has chosen an attack using the wrong stat, they can just fix it up later.