As controllers are pretty much mechanical affairs then yeah it should be simple enough to carry on with making rapid fire stuff for.
Most rapid fire mods are nothing more than a pulse applied to an input (generating the pulse is hour 2 in the learning digital electronics* where hour 1 is learning enough analogue electronics to get by).
*amusingly the 360 controller already has a nice pulse built into it for various reasons (mainly having a light show) and as the Wii U tablet thing will have a clock pulse already there you can probably tap that for it.
Doubly amusing for me is the amount people are willing to pay for something I could probably pull off with the contents of any electronics type's junk draw/$5 and a trip to radioshack and 20 minutes work from unmodded controller on the desk to reassembled and being tested.
Detection... many methods. As Joe88 said you can limit press speed (for various reasons such a thing has kind of happened for years anyway). The obvious one is most mods just make a very regular signal and such a thing should not be hard to detect. Add a bit of randomness (and assuming you have the timing thing sorted) and you are good.
You do also have to consider switch bounce (switches are typically on or off but they are not perfectly reliable and certainly not on the sub millisecond levels) as you do not want to be calling cheater on someone with a bad or even perfectly functional controller.
Power usage/resistance measurements. Maybe in extremes but just as easily worked around really to say nothing of the dodgy controller issue coming back.
You can try sending a code through the signal lines on top of the general signal for the switch. This only stops the simple mod of jump the main power and the smarter method of take the input from the switch side of things is still there.
MS and co... they seem somewhat tolerant of it in some cases (
http://gbatemp.net/threads/evil-360-controller-review.347545/ ) to say nothing of half the stuff
http://revision3.com/tbhs does.
For the record though I do not consider rapid fire mods to be cheating.
Now the making the keyboard and mouse adapters might be a more interesting discussion.