Wait! If I'm reading this correctly, you followed the rules right? You didn't send a 2 page resume to a school that specifically limited it to one page?
If so, you're blowing this way out of proportion!
Just because you can fit everything in one page doesn't magically make your resume better. I stuck to the one-page resume because I knew a few of the schools I was applying to limited it to one page. It was just easier than have two different resumes.
Considering the content would likely be very similar (if you went back and reduced it one page) I wouldn't worry about it at all.
The adcom isn't going to hold up your resume (2 pages), then another guys (1 page) and say "This is a easy decision!" and ding you right there!
I swear, the whole b-school application process really messes with peoples heads! (mine included!)
RF