Quick question

Im just wondering, does GW have any type of threat system? it seems to me that in pve the mobs will just automatically run for the monk or second squishiest target in the group (if in range) is this the case or is there a real threat system in this game

anet tried to make smarter ai. why go for a warrior with 80 AL when there is a nice little ele or monk it can take out easy.

i mean like is there a 'meter' that certain classes build up? (similar to wow you could say)

There isn't really any threat "meter" to say, but it is more they go for the weaker char.

well if you want to tank sufficient you should tell everybody else to stay back while u go aggro the stuff once theyre all pounding on you the rest can move but beware an aoe could ruin the whole tanking process

If you are tanking, there are two nice guides in the Community section. This an art you have to work at to be proficient - not a lot of help from the AI.

If you are a squishy, AI is programmed to go for the lowest armor/health in aggro range. With the "new & improved" AI, that range seems to extend a long ways. Kiting or even downright running away is a basic skill for a caster.

NOTE: They still seem to ignore mesmers though.

NOTE 2: They also seemed to be programmed to lure melee fighters away from mob by running away. Learn to break off in order to stay with the main fight.