We were at EPCOT for my son's 3rd birthday. If you go up to a CM (that doesn't have a lot to do) he/she can call a special number and have a recording of Goofy saying Happy Birthday.
Our CM was an international student from Germany, and I'll never forget her. I think she was just as excited as we were.
Have a great time!
PS - I would definitely do a character meal and let the host/ess know it's a special day. We had my son's first birthday (yes, he's a lucky kid) at Chef Mickey, and Mickey actually sat on the floor and played with Matty's presents with him. We just watched the video (he's turning 5 when we're in Disney next month) the other day. It was awesome.