I agree with the others.
When I applied for my undergrad program, it was done online on in January. I had an acceptance later about six weeks later.
The grad school application was also done online, but I had an approval in three weeks, even after they'd told me it would take four to six.
If you've mailed it in, and it's a very large school, I'd give them at least four weeks and expect that it might take two months. Online applications seem to take a bit less time, but not much.
My on campus organization (that I chair) has an advisor who is the head of admissions. Right now, most of her time is spent on open houses and going to various college fairs to solicit students to enroll before the December 1st deadline for some of the programs. In seeing that, it may be possible that the school you're applying to is doing the same thing. This leaves less people on campus to review the applications that do come in.
Good luck! I know the wait seems to be so long, but the earliest you'd be in the classroom is next semester, right? You still have plenty of time.
