Even in normal groups, not even raids, you are Going to NEED a Cleric in a lot of zones, and I really doubt anyone is going to turn down having a Warrior join also.
[You must be logged in to view images. Log in or Register.]
DPS is going to be a lot bigger deal than it is now. I don't see people rushing to invite a Wizard that is afk, OOM, no more than they will want a AFK, one song wonder Bard in a group either in Velious.
[You must be logged in to view images. Log in or Register.]
A lot of groups in Velious are going to be a hell of a lot more serious and picky members wise. There will be lists on who is worth a crap and who is not for sure. Terrible pullers, crappy CC'ers, afk'ers will be weeded out in a hurry.
[You must be logged in to view images. Log in or Register.] Velious will be hard mode, not easy mode like now.
[You must be logged in to view images. Log in or Register.]
And like it or not, a Ranger with their track, is going to be a NEEDED addition in a group to see what named mobs are up and where. You want good gear and loot a Ranger is the one to make that happen a lot more than not.