The world will be watching slightly less porn in the next US-Russian stand-off...

Do many European companies use US based datacenters for their core systems? Even before the Snowden revelations I would expect latency to push many to not do so.

I guess it would rather affect smaller companies who rely on infrastructures like salesforce.com or office 365 (not that I have any idea about where these two examples store their data).

Also wouldn't all the .com and .net domain become unresolvable once the TTL have passed? That could create havoc.