I found several interesting articles out early this morning and from late yesterday. These are worth checking out.
Hair Fair runs from July 14 to 29. This is a huge event and a great opportunity to help out the non-profit Wigs for Kids. This event is usually crowded and lag is a significant problem. A number of things have been done to alleviate lag. Most everything in the regions is non-physical, meaning you can walk through shop walls and fly through the ceilings/roofs. The idea is to reduce the collision information the regions must calculate.
This year they have ideas for personal reduction of lag that I have not heard before. One is to set the Debug Setting: RenderAvatarMaxVisible to 5 rather than the default 35. Press Ctrl+Alt+D to add the ADVANCED menu item to the top menu. You will find the Debug Settings in Advanced. Type or copy RenderAvatarMaxVisible into entry field and change the value. At some point after leaving Hair Fair you will want to change this value back to the default 35.