Intellij now makes use of JDK 6 which means that one should upgrade his version (using synaptic you know the drill) and set IDEA_JDK to /usr/lib/jvm/java-6-sun at the .bashrc file.
But wait! thats not all!!
The upgrade that youv just made has changed the default Java version symlink (under /usr/bin) which is used in your bash!, this means that any bash invoked application (maven, JBoss) will use the new JDK instead the older one (a big no no if your still developing in 1.5 like me).
sudo update-alternatives --config java
Another pointer that i have found to be useful is to make sure to delete the older .IntelliJIdea70 hidden folder, that in case that you have used the M2 idea version prior to the final release.
Thats all, Idea Rock on!