First of all, thanks for prividing an OSX bundle for build 689! Secondly...it doesn't work ;)
The reason is that from DP8 onwards, apps have to explicitly specify that they require 1.4.1. This is done by specifying a JVMVersion key in the Info.plist file. Attached is my own Info.plist which does work.
Also, choosing options -> file templates throws up an internal error (i'll file an SCR shortly). But it's getting there!
Also, is there any chance of you providing a 128x128 version of the IDEA icon? Would be nice to create a really good looking .icns OSX icon for it ;)