well Insider says "No cpu update"
I have to correct you on this - Appleinsider quotes Gruber from Daringfireball who says:
"CPU performance remains more or less unchanged across the board: (...) 1.6 / 1.83 GHz for the MacBook Air."
The current C2D used in the MBA operates at 1.6 and 1.8 (and not 1.83 Ghz). 1.6 and 1.83 Ghz would mean that (as I hoped/predicted) Apple indeed will update the CPU and use the LV C2D 45nm processor instead of the current custom-made 65nm solution.
The update wouldn't bring a large increase in performance but solve the heat issues and bring better battery life...
EDIT: Correct me if I'm wrong but I assume that the custom-made form factor is something pretty costly for Apple. My assumption is that if they use the new NVIDIA Chipset, that doesn't need a seperate North- and Southbridge but only uses one chip, there might be enough space on the logic board for a "regular-sized" FCBGA6 CPU.
EDIT2: I just noticed that the Penryn LV C2D actually operates at 1866 Mhz. 1.83 Ghz stated by Insider et al seems therefore to be a typo cause the current MBA runs at 1.8Ghz and there is no such thing as a 1.83Ghz Penryn.