For those paranoid about "online voting" - this is nothing of the sort, it simply updates the county voting registry with your details, they do a human effort to match it up with your existing info.
Now if only the swing states had this in-place, it could enfranchise millions of folks who can't/don't have the time to register or don't realize they might have missed the registration deadline.
It wasn't your point, but why would a hypothetical online voting system be a problem? If, as another poster mentioned, this online registration system is good enough to prevent erroneous registrations, why couldn't the creation of an online voting account be included as part of the of the process? Being able to register and vote without leaving your desk (or on your phone, at home, etc) would help to enfranchise the aforementioned nonvoters even more than just making registration more convenient would.
If it's at all in doubt, I'm not trolling here, but genuinely curious as to what the fault(s) in online voting would be. The main problems that come to mind are (theoretically) preventing the privacy of anonymous voting and the possibility of cracking accounts (given a user base close to the entire population of a state and an (imagined) incentive for doing so, brute-force guessing of stupid passwords would likely be very effective if proper password complexity checks were not put in place), but what with the scandals that voting machines have caused in the past, I'm not so sure that offline voting systems are more secure in practice.
Good luck getting that kind of assurance with the voting machines. Lack of paper trail is a gaping flaw.
So, yeah. I'm pretty sure it's a least-effort-without-getting-fired delivery protocol.