For the first time in history, a major part of this voting is done on voting machines running on top of a general-purpose operating system.
The three largest manufacturers of voting systems (Diebold, ES&S and Sequoia) all run closed-source systems on top of Windows. You would think that voting machines would be a prime example of systems that should be open source, so anybody could verify what exactly happens and how. And there is a long list of known failures so far.
We might also remember that Diebold is one of the largest manufacturers of Windows-based ATMs...and that RPC and LSASS -based network worms have managed to infect such cash machines in several occasions over the last year and a half.
So it will be interesting to see how everything plays out.