1.6 here and I have yet to hear any noise whatsoever fan wise.
It is certainly cooler on the lap than either the macbook or macbook pro too.
What are you running? I have noticed now that a single office app and safari/firefox plus a streaming JAVA window (i.e. ameritrade stock streamer) will definitely kick the fan in to maximum. Turn off the JAVA window and the fan slows down (as does the cpu load).
I have noticed time in and again that JAVA is just horrible on OS X. The Java windows/apps are slower on OS X than on my five year old Windows XP laptop. A great example is trying to resize an Ameritrade streamer JAVA window. It is instantly responsive on Windows, slow on my iMAC core 2 and its truly like molasses on my Air.
If you are stock trader (I am not) who depend on these windows, Air is not the right platform for you. The terrible JAVA performance on my Air is making me consider returning the Air and swallowing the restocking fee....