When NXE launched, it was pretty quick; however, over time, the dashboard has become noticeably slower.  Thankfully, even Microsoft acknowledged the problem and a fix is on the way by the end of this year.  However, don’t just call it a performance enhancement for God’s sake.  Taken from Major Nelson’s podcast:

“The team has done some really good stuff around making performance enhancements. ‘Performance enhancements’ doesn’t sound right because it sounds like we’re going to give the guide a little blue pill, and we’re not doing that. Whatever we call it (and it’s not going to be called the NNXE), but whatever the next version of the dashboard is called, it’s better with a lot of very cool new features. That update will be out later this year”

New features?  It’s safe to say that Twitter and Facebook compatibility (just to name a few) will be released alongside the update.