I don't know that you're going to be able to VNC directly into a Hog 3/iPC/Full Boar. All of these have custom-tailored operating systems (Linux and WinXP Embedded respectively) with a lot of stuff stripped out.
However, I am planning to try a VNC connection from my iPad into a Hog3PC computer (on a laptop networked to a Full Boar). I expect this will work fairly well with the Hog3PC computer as a client of a network show.
This is obviously one more piece of gear than would ultimately be ideal, but I think the most likely solution rigt now.
It's worth noting that there are already people using tablet PCs with Hog3PC as RFUs already. This certainly has the advantage of connecting directly to a network-enabled console without the need of an additional computer.
It would be great to hear from the developers as to whether enabling a VNC connection to the consoles would be a possibility in the future.
Seems to me that this would be a fairly smart way to add versatile RFU connections to the Hog 3 family without too much development time spent on custom apps.
I'll let Brad Confirm or Deny this, but I believe one of the functions they are hoping to have in the iPad Hog App is the ability to pan and tilt fixture(s) using the accelerometer and actually tilting and panning the iPad.