BugSack + BugGrabber on the error catching front are working just fine, they don't need an update really.
Great, I was worried that it wouldn't be as effective having not been updated. I suppose I could just update the Interface version in the .toc file.
That's about it off the top of my head, mostly the wow client itself is the debug tool.
I've been relying 100% on the client for debugging so far but wanted to make sure I was seeing every tiny error that even the client may hide (not sure if it would).
I also use an xml validator in my external editor (UltraEdit) and look at FrameXML.log to catch those hard to debug .xml file errors (when I have to deal with an addon that still uses xml for frames; a progressively more rare occasion)
Is this WoW XML validator an acceptable tool to use?