Yes, the 2 GHz barrier is actually one that several HD video playback apps require for HD playback. For instance, iTunes HD video requires a 2 GHz CPU.
For those wanting to spend less, buy a refurbished rev B MBA with 1.86 and SSD for $1449. Probably brand new reboxed, and $50 cheaper, with same warranty and software, AND SSD!!! Which makes the biggest difference in the MBA. Without SSD, the MBA is a nice little Mac. With the SSD, the MBA is the coolest Mac ever, it's fast, it's fun, it's ultra portable, yet it feels like a Mac Pro!
BUT, for HD Video, I would recommend everyone get the 2.13 GHz SSD. ALSO, I noticed that I haven't had one stutter, nor one spinning ball, and have had excellent playback of all video on this new MBA!