Yes, keep in mind that the MBA is designed to act as one giant aluminum heatsink. When you open it up, there is a plate over the CPU and GPU heatsink that transfers the heat directly to the case.
That being said, my MBA Rev. A 1.8ghz gets up to 90-92 degrees C at the cpu according to istatpro when playing youtube videos. During normal use, it's around 48-60C.