Why do you want a "press pass"? Are you shooting for pleasure or are you a member of the working media? Which game are you planning on attending?
Since you ask "is it even likely theyll allow my 40d past the gates?" it sounds like you're going to be in the stands anyway.
Like all of these questions, it doesn't matter what anyone on this or any other board tells you, the only opinion that matters is that of the credentialing body. Since these matches are under the auspices of US Soccer, more than likely this is the organization that will be controlling access for working media.
I just shot the US MNT Vs. Brazil match in Chicago last month, and credentials for this match were issued to a wire service for whom I shoot, and they were issued by US Soccer. Try by going here and registering:
Odds are, unless you are "working media", you won't be approved for credentials, but it probably doesn't hurt to ask.