Can you export a list of registered users who've registered for an event via the registration module?
Out-of-the-Entity-Registration-box you will (to my knowledge) not get such export facility that you are asking for, so the short answer is NO.

But Sales starts when the customer says no ...: have a look at the Community documentation of the Entity Registration module, especially to this part of it:


  Not happy with the default tabular list of registrations? No problem,
  registrations and their fields are all Views friendly. You can override the default event registrations list, create additional ones, etc.


In other words, if you're willing to accept, as a compromise, to get other modules involved, then it should be pretty forward. However with only views you still don't have the "export" function yet, and you'd need another module on top of that, like the Views data export module (or any of the "similar modules" mentioned on that project page).

Unless you're open to an alternative module for this views-and-some-other-module(s) approach ... I.e. if you'd be willing to only consider the Forena module (disclosure: I'm a co-maintainer), you'd have your 1 stop solution (only 1 extra module, that can do everything you are asking for). Have a look at it's community documentation to get the idea about it (or look at the answers to some of the forena questions). Or post a followup question like "How can I do this with the Forena module?" (to avoid you'd have to change your question here to a chameleon question).