Assuming you meant NYC, the problem for Hailo/Mytaxi/etc is that yellow cabs are only allowed to pickup street hails and can not be dispatched to you directly. So unless such regulations are loosened, these apps just won't work.
Bravo to the folks at DNSimple for being on top of communications during this time. It's something that they themselves brought up less then a year ago during the Zerigo DDOS (https://news.ycombinator.com/item?id=4280515) so it'd good to see them sticking to it.
But it also seems as though the same advice proposed in that thread should have been used by their customers: Namely, utilize multiple DNS providers to mitigate risk, and choose providers with IP anycast. Heck, even setting up your own secondary DNS on a $5/mo cloud server would keep your site up (unless of course your site is the main target of the DDOS).
I actually believe this testimony is from the mid 2000s (Tom Feeney was in congress from 2003-2009).
While in the video, Mr. Curtis has a point that voting code should be reviewed by independent experts... even if the code has been vetted there could be code injection through the operating system or compiler, however unlikely. And that's not even considering anything malicious with the network or databases. There's simply too many moving parts in electronic voting for it to ever ensure 100% honesty. Possibly making it law to require a hand count of all receipts/ballots to ensure a match would catch the fraud afterwards, when time is no longer such a factor. Or better yet, running paper ballots through two separate electronic voting systems by each voter and comparing counts.
But to answer your question, no I don't believe anything has been done.