It would be cool if the addon had default mob priority lists for all TBC instances. Right now, out of the box, it seems to mark the first moused-over target with skull, the second moused-over target with star or cross (depending on setup), etc. It would be so cool if it scanned all mobs in the pack (all mobs alt-moused-over in the last 3 seconds?) and marked them based on kill priority.

According to the readme this can be set up manually, but it would be very handy if this came out of the box. The really 'hardcore' players could then still change it to their liking, but for average players auto marking should really do the job.

There's another addon for this, MagicMarker_Data. It's kind of a subjective deal too, and it's difficult to do - different guilds have different preferences. In either case, that's the goal of the the MagicMarker_Data addon