Hey man! Welcome back to EZ!
I've been in a similar boat, took a couple year hiatus, came back and T5 and Strike 5 augments weren't end game anymore.
With the advent of free waypoints through donations you don't see the classic guild structure nearly as much. Since Hunter made it easier to create instance and invite other people into guild instances, you'll find people will stick to their own box guild and just raid with friends they meet, taking turns killing in each others guild instances (and repopping them, if you've been generous enough to acquire free waypoint clickies).
That said, keep an open mind and stay vocal in /ooc if you need help with anything or wanna team up with someone. Look me up in game and i'll help ya finish up your 4.0s and T4 stuffs and move into T5.
