It was very important as a p-book and still as important as an ebook. Sometimes I won't buy books based on their covers and sometimes I do. I still judge books based on their covers.
When it comes to ebooks, I would rather covers be nothing but boring text than some of the ugly, cramped covers I've seen. I really wish indie authors wouldn't do their own covers. Of course, a lot of those non-covers are of classic books so I know they'll good.