There's actually alot of things they could fix to improve the user experience. Just signed up for an account and it wasn't overly pleasant. List of a few gripes:

  * No ajax on name availabilty

  * very limited secret question options ( min of 5 chars for answers)

  * Wasn't overly obvious which fields were required until you hit submit ( in the end I think they were all required)

  * Initially there was a smug looking guy on the login page(pretty nitty picky) he seems to be gone now but if goto www.outlook.com you get a broken image