Just possibly Eragon reads like Eddings because the two draw from the same source (mostly JRRT) which was itself drawn from older sources. Both works, along with Brooks et al, are almost blueprint uses of Joseph Campbell's hero's journey (CF "the Hero with a Thousand Faces.")
As to characterisation, both use Campbellian archetypes almost straight off the page. This being the case I can't say that either Paolini or Eddings does a great job of characterisation. Tolkien did better and he was conciously trying to use the archetypes as archetypes. Much as I enjoy the Prose Eddings as a light read, his characters are thin and repetetive.
sigh, Darv, Sword of Shannara and Lord of the Rings are disturbingly similar stories. if they were both taken from an earlier story, thats cool, however I have yet to see a similarity between the Eddings' works and Tolkien. Paolini's works? as I've said, his stuff classes more fanfic than anything else, anyone who has read McCaffrey's stuff, watched star wars, and read the books licensed in that universe, etc... will usually find ideas and concepts straight out of it. The only point I've heard, aside from the similarity of main character being orphaned and raised by an "uncle" who dies.... standard once upon a time setting usually... is magic being loaned to creatures without it. Eddings had that in the Elenium series, I don't know where it might have come from in an earlier incarnation.
As far as the Eddings characters being "thin and repetitive" those characters are the best representative of characterizations I've seen. Yeah, a couple characters are fairly imperious, but there are others who fall under the everyday Joe heading. and these characters are true to who they are. no everyday joe who suddenly knows everything thats going on, no feeling that the female character is some fantasy in a guy's mind, or worse, a picture of a guy cross dressed, acting the part of a woman.