The Windows Live team has posted a YouTube video showing the speed difference 6 months can make with their updated Hotmail web email client. It sure has come a long way since the HoTMaiL days. I wonder if my old (OLD) login would still work? 
It appears to be around twice as fast, but I am sure there is some bias in there to make it look better than it actually is, even unintentionally. How did they squeeze some extra speed out of the client? Caching, preloading and asynchronous operations.
Hotmail 2011