i think it's good you know what you're passionate about! social phobia will try to take away the things that make you happy or could better your life. also, too, if no one talked to you or didn't form a group with anyone, that would suck, but i think you would survive! if you don't go you'll probably regret it. there's probably a tiny voice telling you to go and do it, and the rest is saying the oppposite. listen to that little voice- it has a hard time being heard under all the anxious thoughts.
for me it helps to get through stuff if i make a decision and stick to it. like i get really anxious applying for jobs- it helps me to get through it if i repeat to myself "if i do this, it could better my life" or my social phobia won't get any better with me just sitting here or i deserve happiness like anybody else- i have to keep coming back to those thoughts, and keep trying... a lot of times i can't go and do the thing i want to do on the first shot. Like with jobs, sometimes, i can only drive up to places i want to apply, but i lose the nerve to walk in... or times where i have walked in, but lost nerve to ask for an application. or i get too nervous sometimes to even turn in an online application. or i do get the application, but can't face the idea of turning it in. for me, i will eventually get to the point where i will ask for an application and turn it in, but sometimes it takes awhile. but i do have a (parttime) job now, and if i hadn't pushed myself just that extra little bit to go back to a place i had chickened out at, i wouldn't have gotten it.
And if you aren't sure if you're going to go or not (and you may not even really know until right before it starts) maybe at least sign up? that way, if you decide not to go, it won't be because you didn't sign up in time.
you never know, there could be other students looking for a passionate business student like you!