http://www.worldoflogs.com/reports/r...?s=4606&e=5051
Looked at and downed Beth for the first time last night. Our raid comp is a bit wonky at times, so I empathize.
Hunter used frost traps and primary focus was the spiderlings - every other wave or so, he'd need help on adds.
I (mage) focused on Spinners using Frost Nova on CD (as needed) and AE or blizzard depending on distance to spiderlings (my AB percentage is usually 85-91% - enforced AoE severely dropped that).
Warlock did the Bane of Havoc and switched between assisting me and helping with spiderlings.
Rogue was focusing on Drones along with our shammy.
Everyone switched to drones/spiderlings when we were without primary targets.
We flirted with having 1 or no DPS go up on various pulls, and I believe we downed her with the rogue only going up for 1 or 2 of the 3 meteor phases.
Hope the info helps - it's really not a hard fight once you get the mechanics down - I fully expect a one-shot next reset (and also expect to do higher DPS on my end, but whatever).