The game has been playing horribly recently, especially over the last week or two. Hard freezes, temporary freezes followed by crazy speed ups, etc. I have heard from others that these issues have happened since the most recent update, but for me, the issues have emerged more recently. What is going on? What is causing this to be so horrible just recently? Around the initial drop of a patch I kind of expect it, but it's been long enough now that I'm not able to guess at the specific cause.

These issues have happened in both trials I'm progging now (Sanity's Edge and Rockgrove), but overland as well. I've frozen on the character select screen. I've had friends freeze while doing crafting writ dailies. In a trial group, it will happen to two or three of us in an instance, then they will log out and back in again and the issue will pass to other people. It seems to afflict at least 2 or 3 of us at a time.
Something is not right with the servers at the moment and I would like to know 1) why and 2) when it is expected to improve.