Newb here. Thought I would give it a try.
That is If I can open the thing. As soon as I double click it tries to open but it immediately dissapears…any hints?
Check the other thread in this forum. Some other guy has the exact same problem as you!
In the meantime, try running blender from the command line so you can see what the error is. I bet you have the wrong version of Python.
Check the console in /applications/utilities. As you double click Blender, it should output some text saying what’s wrong. It’s usually a Python issue as stiv said. OS X ships with 2.3 as default - there are two binaries on blender.org.