Ive playtested the game using what info ive been able to garner from these forums, and I must say WoW minis has certainly got a sweet system happening - The system is elegant, fast playing, smooth, and exciting with room for improvisation with tactics, and most importantly for me, combat uses an opposed rolling system which to me is a MUST for any skirmish game - Mordheim killed me with its watered down WFB ruleset.
Now Im curious to see how new mechanics can work for certain systems that will enchance the game without bogging it down, what mechanics are you intersted in?
For me, its things like the following off the top of my head
Rogues and combo point finishing moves - there doesnt seem to be enough health on figures to rack up big combos though.
How Hots and Dots work - I play a druid so self explanatory, Lacerates, Rips and Lifeblooms ftw.
Raid and Dungeoncrawl games - I think these will be sellers, I dont expect the dungeon crawls to be overly complex, but somewhere between the level of Descent and Mageknight dungeons. Boss drops could even be things like gear cards which could alter your base stats.
and finally, More Action bar cards per figure - the current play only uses 2 cards per fig, but extra cards allowed give for more unpredictable play.