Although an album's cover technically has nothing to do with how talented or untalented the artist is, it does seem to play a role in helping some people decide whether or not to give an artist a listen.
Personally, I think it's important as part of the whole CD package but it won't affect my feelings for the music that can be found on the album.
I also wanted to add that I think it's awesome when the actual artist designs their own album covers. To me, it just adds to their talent if they can create a good album cover. Look at country guitarist Brad Paisley. Not only is he capable of playing great guitar work and writing some good humorous and serious songs, but he's also designed probably around half of his own album covers, including the cover for his 2008 album PLAY which is a picture of Paisley's 1968 pink paisley Fender Tele sitting on a swing in a playground (the album is mainly instrumental with songs ranging in genre from Paisley's usual country to rock, blues, jazz and beyond). Anyway, here's a link to the album cover for PLAY so you can see it: http://www.guitarnoize.com/images/blog/bradpaisley_play.jpg