This is one of those practical inventions that I could see being in everyone's home (and bathroom) in twenty years, with future generations asking: "Did people really use unhygienic towels to dry their hands after washing, grandpa?"
The evidence seems mixed or against air dryers, at least when compared to paper-towels, properly implemented. See for example:
http://online.wsj.com/article/SB1000142412788732470510457815...
http://blog.kamens.us/2010/10/26/dyson-airblade-not-the-fast... (including the University study linked within)
I'm not a fan of the Dyson jet dryers. I can feel the mist of blown water, suggesting that it's getting my 'bathroom sink rinse' more places, rather than leaving it all in the bathroom. The power of the jets sometimes causes my hands to touch the sides of the device, which results in one more bathroom-surface-touch than I'd prefer on my way out. And unless I run my hands through 2-3 times, waiting for the unit's (motor cool-down?) pause each time, my hands still feel slightly damp compared to a thorough paper-towel-drying.
A DIY version of this concept is on my list of "projects I lack the expertise to do safely or effectively, but I'll be damned if that stops me from wasting hours on ill-conceived diagrams and hundreds of dollars on parts".
I think towel is still better for home usage as it wipes any remaining soap/stain off your skin in hard to reach places, and after a while you can always wash it in a washing machine.