That is the unfortunate caveat of the wait list. They really do keep you waiting!
There are various tips and tricks for handling your time on the list -- check around the forums, but I'm speaking particularly of responding to the wait list with a kind "Thank you, I'd like to remain on the list, I'm still very interested in attending the program" and perhaps (if you have it) an updated CV with any recent accomplishments/awards -- but there simply isn't much for you to do but wait.
If it's unfunded, they have 16-20ish people, and you're #10 on the wait list, my extremely uneducated guess would say that you have even odds. If the program is new at this school but exists in other schools, I'd say your chances are slightly better. Lower if it's an entirely new program with no analogues.
"As far as 'hanging in there', I'm 'hanging' all right... but maybe from a rope if I don't hear soon from my other schools."
Hah, I know the feeling. Sorry for the cliche. I do hope your programs get back to you soon to alleviate some of the pressure!