Patience. Lots of it.
You get paid to think when other people don't necessarily want to (or can). Some support issues that come your way arent "issues" at all, or the solution is right in front of the end user, but they dont want to think, so they call you. You'll find that some end users will rely on you for everything, while some "know enough to be dangerous", and then call you when they break something :). The better you get, the more you are relied on, and eventually will get asked to do everything from install a car stereo to "fix my botched exchange install that I tried to do myself by 2pm"...
People skills,, the ability to interact with the end user in a pleasing way --- even though you may be frustrated. ("fix your exchange server by when?")
Ability to identify the issue quickly and more importantly correctly ("you don't know what outlook is?")
Ability to solve a given issue quickly, correctly or find an alternative that may even be better (think outside the box --- "hosted exchange might be the solution you need")
The desire to keep learning, constantly.("time to pull out the exchange 2010 install guide")
The ability to speed read ("lets see, so its 1:25 pm now...")
Patience. Lot's of it.