I find it a bit strange how the disguise skill changed. Now it appears that you can only use it on yourself, which is a bit absurd. Why shouldn't the bard be able to disguise the fighter. As it stands, a character can only help someone else to use makeup, to dress up etc., granting her only a +2 bonus.
I think I do understand the reason for this change since a good disguise needs more than makeup and dresses. But this is a skill in which someone elses help should grant a greater bonus...
A disguise is far more how you act than how you look.
If you really wanted it to make more of a difference, you could adapt the "improved Aid Another" from the old Epic Level handbook - roughly speaking, the more you beat the Aid Another DC by, the greater the bonus they get.