Oatmeal,

The average wait between Phase I and Phase II is not something anyone can really tell you.  Remember, after passing Phase I you aren't guaranteed to even get a shot at Phase II.  It really depends on how competitive you are relative to the other applicants that passed Phase I.

At this point the Applicant Coordinator is looking at the FD-140s of all eligble applicants and selecting the most competitive to move on.  Specifically, he/she is trying to match backgrounds with the current critical skills list for further processing (view the vacancy announcement at www.fbijobs.com for a list of the current critical skills).   

Your chances of reaching Phase II depend solely on the skills that you are able to bring to the Bureau.  If you possess one or more critical skills you'll most likely be offered a Phase II slot.  Hint:  if you have a computer science/IT background you WILL get a shot at Phase II.   

If you've never been in touch with your AC, give him/her a call.  Just make yourself known without bugging the hell out of him/her and see what happens.

In any event, Phase II isn't what you need to worry about.  Phase II is simple - if you're qualified to be an agent and have the traits the Bureau is looking for, you'll pass.  The polygraph is what you need to be SERIOUSLY concerned with...  good luck.

Also, check out www.911jobforums.com/vB if you haven't already.  You'll find a lot more hiring process information there than you will here.