An interesting idea, but a lot of extra work just for the "coolness" of an iPad. If you already have a small PC and a VCDS cable, the iPad is not that big of an improvement. If it is just wireless you are interested in (not "coolness"), the same thing is available from Ross-Tech. I have run VCDS on an iPad without the use of a duct taped PC and router combination. Unless you already have an old netbook and wireless router laying around the house, it would be cheaper (and a lot easier) to buy a Hex-Net wi-fi interface from Ross-Tech and run VCDS-Mobile through Safari or Chrome. The only downside to this is that to get full VCDS capabilities, you need to be connected to a wireless network with internet access (the Hex-Net and the iPad must be on the same network). An iPad cannot connect to 2 wireless networks at the same time.
BTW: The Hex-Net interface also works as a wireless interface to a Windows computer that can then run the full VCDS program with no restrictions (requires Beta v14.x).
Have Fun!
Don
If you were starting with nothing, the HEX-NET interface is certainly a good option, at $399, or $499 for the unlimited version.
In my case, I already had my HEX-COM+CAN cable, which was $349. The router and computer I used were things I already had laying around gathering dust.
Also, since mine is a fully functional Windows computer, it'll do anything.
One thing I wouldn't try to do with it is cross the border, or take it on an airplane. A bunch of circuits and wires, and an antenna sticking out from a bundle of duct tape... Hmmmm.... I think I'll leave that out of my carry-on bag...