Sorry dor digging this old zombie, but while searching the topic about plugin delay compensation I've found this.
I agree with bv, it would help a lot for some instruments with long attack, but it will help even more to fight some plugin's delay.
I've been demoing some VSTs which add an awful lot of delay when processing, and the result is unlistenable. So I'm guessing this feature would be a nice addition.
Still hoping the normal delay compensation will be realized some time.