So, including SCORM 1.2 support 'out of the box' seems the obvious choice
Because we use the excellent pipwerks SCORM API wrapper, implementing SCORM 2004 is generally as straightforward as just switching over to the correct imsmanifest.xml* and commenting out one line of code**
In terms of what is tracked in SCORM (and how it's implemented in the UI) - Kev Adsett is probably best placed to tell us what the current functionality is. Though I do know it does not support cmi.interactions tracking at this stage.
I'm guessing we'd all like to have support for Experience API (AKA Tin Can) on the roadmap - but what about AICC? In my experience it's little used in the UK but is strangely popular with our US cousins across the pond... I personally have very little experience with it, so would love for somebody with more experience to volunteer on this one!
* and supporting files - of which SCORM 2004 seems to require an inordinate amount
** which forces the pipwerks wrapper to default to SCORM 1.2 for those odd LMSes that make both versions of the API available