Since this last update on TF2 I only saw fit to add this group, as I think it may be the final group in weapon/class specialist, joining the ranks on Class Specialist:

Battle Engineers United – [BEU] – http://steamproxy.com/groups/BattleEngineers

As said before if any other groups feel they fit in the Class Specialist, plz message me.
But for now it seems all classes have been filled with there Specialist Groups, and will rise to bring fear into others!

Four of our own home grown CnB specialist Groups have made the cut into Class Specialist:

๖ۣۜBlazing ๖ۣۜShadows

Heavy Overload Explosion

Führer der Blitzkrieg

Corps of Engineers

All these groups are not to be underestimated and defintly feared, runaway.wav! A fine addition to the many strong class groups that makes the Class Specialist what they are!