The fact hypershade is slow is due to the time it needs to load all the materials, preview..It's always been slow.. but with 2011 it appears slower..sigh.. However I didn't notice sluggish in other aspect...The select tools, move tools settings which used to be slow is now more reasonable.
Maya 2011's Hypershade is definitely super-slow to open, for me. It was fairly slow in Maya 2008, but it's definitely slower now. The rest of the UI seems as responsive as ever though, the worst part is always the Attribute Editor if you have a lot of history in your selection. Takes ages to refresh, but then again it…