Sorry to hear about the deposit thing. At least (as has already been mentioned) it could be much, much worse (don't the DO schools only give you like 7 days to respond as well?)
You'll see all along your medical training that there are so many people applying for so few spots that the schools/residencies/etc can really do anything they want. Sure, they've made the $100 deposit nonrefundable now, but if you aren't willing to pay it there are 500 others who would write the check in a heartbeat. So if you're interested in the school you'll do it.
I'm sure other places will start turning the same way in the near future. For residency interviews, if you enter more competitive fields many of the programs won't even pay for your parking for the interview day. People who are interviewing for less competitive residencies are getting free hotels, parking, meals, gifts, etc.
Congrats to everyone in the thread that has heard good news, though! And to those still waiting...good luck!