Not ready for prime-time. :) Doesn't actually save pages (just updates the live view), and seems to have problems when invoked multiple times.
Not all GeSHi languages are supported.
Colors of course are different.
Set $wgCodeEditorGeshiIntegration = true to enable; adds a 'section edit link' on source bits.
Simply using the existing gadget version modified to load Ace from the extension directory for now, will integrate better into WikiEditor and use ResourceLoader to load Ace itself in upcoming commits.
