Yea I bought the MBA just about a few weeks after it was released and I did love everything about it except for the fan noise was too loud. The heat was about the same as the macbook so its tolerable but the fan noise is the only reason that bothered me. Surprisingly the mba that I had was able to play 720p trailers just fine without stuttering problems.
But if I do purchase it again.. it will only be used as a websurfing machine only and maybe a youtube video here and there but its just the fan kicking in at 6000 rpm that just bothers me from just playing 1 youtube video.
Well if fan noise is your only beef there is an easy fix for that....
Because MBA's fans randomly spin up even though the processer is cool, you can install a program called SMCfan control, and then in the terminal window apply:
/Applications/smcFanControl.app/Contents/Resources/smc -k F0Mx -w 3e80
this will limit your fans to 4000rpm....
/Applications/smcFanControl.app/Contents/Resources/smc -k F0Mx -w 60e0
Put this in and it will restore it to the default setting (or if you're going to do something intensive
basically I've done this and never hear my fan ,even with youtube or 720p vids... I'm also running coolbook so I never see the temp go higher than 75 degrees
so here is one way to overcome your problems.