I read this short post by Nathan Bransford about tinkering with e-books after they have been “published.” At first, I was deeply conflicted. On the one hand, being able to correct typos easily and make updates seems like you would be giving your readers a service they could not get in print books. On the other, my English degree (my old, tattered one) says that once a writer releases the work, it is no longer his; it belongs to his readers, warts and all.
But then my old newspaper background reared its ugly head and reminded me square on that in print, there are no do-overs. If you miss a typos or make some other mistake during the editing process, it will get replicated 200,000+ times and be forever archived AS IS in the Library of Congress, the Newseum and as clippings in scrapbooks for generations. If that kind of pressure does not force you to become very, very good at the craftsmanship of writing, you should perhaps look for another profession.