As the guild progresses further and further into the antechamber of Ulduar, we should be expecting a higher frequency of "wipes." Fights become more and more complicated--so this should be the natural tendency.
The deeper we delve into the content, the less the margin for error becomes. A heal that doesn't get off in time, a spell-steal that goes awry, a misplaced interrupt....all have the ability to wipe a raid. Take into consideration not having a lock for soul stone, or a priest for mass dispel, or shaman for bloodlust, and that margin further closes.
As wipes go on, practice makes perfect--and the more often we engage in an encounter, the more we learn, the better our reaction time gets, the better we are able to theorycraft strategies for it.
I want to remind everyone, that progression comes with a price...and although sometimes that price is measurable in gold, the actual cost hinges on our resiliency. If we want to survive as a group, we will need to learn to wipe with dignity. This means getting back quickly, rebuffing, swiftly discussing the things that went wrong, how we can make them better, and then climbing back up onto