Looking at NS records today some of yesterdays affected companies decided to change things after the DoS on Dyn. As the NS record is not really a customer facing feature this is more an indication of Dyn's customers expectations. One could argue switching away from Dyn could mean fear of more downtimes to come. Here is a summary of changed NS records so far:
SiteBefore (15.10.)After (22.10.)
about.com dynect.net nsone.com
etsy.com dynect.net dynect.net
awsdns
github.com dynect.net awsdns
paypal.com dynect.net dynect.net
ultradns.org
paypal.com
xhamster.com dynect.net anycastns*.org
zendesk.com dynect.net ultradns.*
speedtest.net dynect.net awsdns
I did only check some NS records for changes, just several of the top sites. There are two note-worthy non-changers being Twitter and Github though, everyone else seems to have mitigated. Some to using two providers, several switching to AWS DNS or UltraDNS exclusively.