I upgraded to Kubuntu 14.04 and have tested running and building O, using todays Git.
There were no problem compiling or running with wxgtk 2.8.
Compiling with wxgtk3.0 worked as well, but a few plugins in my tree had problems: gradar, logbook konnie and FindIt.
With both wx 2.8 and 3.0 installed O found and used 3.0.
But .... there is a run time problem. Trying to start O I was greeted by this dialog, that I've never seen before:
From the command line I had this
*** Caught unhandled unknown exception; terminating
../src/common/wincmn.cpp(478): assert "GetEventHandler() == this" failed in ~wxWindowBase(): any pushed event handlers must have been removed