Both Skype and iChat video are important to me, so I ran some tests on my new (1 week old) MBA. First, I skyped from NYC to London over a high bandwith cable connection. The party at the other end could not really tell the difference from my 24" iMac quality. This was a bit surprising since the MBA camera is clearly softer and has less dynamic range than the iMac's. Next, I waited for the fans to get up to 6200 rpm, which they will during a fullscreen skype conference. The other party could not hear the fans, and said the audio quality from my built-in mic was fine.
Next, I was worried about load, "stuttering", and the "core shutdown under load" issues some users have had. I set up two macs in my office (72 deg F) and skyped them together. On the MBA, I ran fullscreen and made sure the image had a lot of motion during the test. I also had a few widgets, firefox, and activity monitor running. I let the conference run 35 minutes. The core temps quickly ran up to 76-78C, and the fan rose to 6200 rpm. The iStat/activity monitor showed between 15-30% idle CPU capacity, and drifted back and forth between those extremes. I never experienced stuttering or a core shutdown issue, although I'm sure adding more load may have got me there. The conference ran smoothly. Then I did the same with video iChat. Very similar results (via Bonjour), although iChat seemed to used ~5-10% less CPU than Skype on average. Video quality was pretty comparable. I also compared fullscreen to a small window and noticed no obvious change in CPU load. After the chat ended, the CPU temp dropped immediately, but the fans took 3-4 minutes to drop back to 2500 rpm.
My conclusion.... Video chats work fine on the MBA, although there is not a huge surplus of processing capacity, and running other cpu intensive tasks while chatting is not a good idea.
