Don't worry about it. You'll have plenty of time to bond with your classmates come July. 🙂
The orientation is useful if you're looking for an apartment, but other than that, you're really not missing that much. Many of the accepted students (like you) can't attend, and quite a few who do attend the orientation end up going to different schools.
Because I have nothing better to do with my life, I just looked at the picture they took at us at the orientation for 2004. Of the 48 people in the picture, about 36 are now my classmates. There are about 80 people (give or take a few) in my class now. Quite of few of them weren't even accepted at the time of the orientation. I don't think that anyone missed out on a life-changing experience by not attending, but you never know. 🙂
Bests,
Paige
Cornell University '00
UMDNJ-SOM '04