Are there any apps or tools that allow visualizing multitouch finger positions for iOS screencast/recording? I'd like to have a visual indicator of multitouch finger positions as I record the iOS screen of an iPad using AirPlay. 

This seems like something that would require a jailbreak. Luckily I do have my iPad JB'd but my searches have not turned up anything.
I needed the same and searched a lot. In my opinion there are three solutions:


Live capture of the gestures one does on your iPad (not professional)
Using a PNG of a pointing arm (hand) in ScreenFlow (or Camtasia).

This works quite well. One can tweak the png a bit (X,Y,Z-coordinates) and with adding video actions it comes to live. It is elaborate though, but with some patience and expertise quite professional.
Buying a M4A or MOV of finger gestures.

Have a look at VideoHive's Touch Screen Finger Gestures for example.

You can purchase them with an alpha channel to incorporate in the screencast. Didn't try that one, but seems the most professional to me. Some costs involved though.