You getting hit in a time of change. This can be good for you if you get a good lawyer who is updated on p2p laws.
First your on a wireless network, so you could fight that the downloads can't be linked to you since anyone could be using that connection. However you said the IT guys were able to track it back to you. This could make it harder to argue the open network.
The RIAA tries tries to bully people into paying and not taking the cases to court. If you do have a good lawyer there is a chance you can win the case if you chose to go to court.
I do recommend moving your files to an external drive and SECURELY wiping you drive
http://dban.sourceforge.net/ that way they wont have any evidence on you unless they get your external drive. (besides the ip logs and such, but no actual file)
see if you can get this person Johan Pouwelse to testify at the trial. She recently shut down RIAA expert in a case
http://torrentfreak.com/riaa-expert-...petent-080221/
Good Luck.