Originally posted by mpp
It depends on the school. Some schools are quick at sending out award letters. Others take a long time. So don't get your hopes up that all the schools will have something to you by May 15. This is a great question to ask during your interview day. Often there is a meeting with the financial aid office. Ask when they send out award letters.
Yes, you can hold onto as many acceptances as you want, for whatever reason, up until May 15.