I don't have any particular beef with those candidates, other than the fact that they may be too pretty, but what can you do—its Hollywood. Joseph Gordon-Levitt is probably a little too old for the high school setting of the new story, and seeing as his name hasn't popped up in a while in the news concerning the project, who knows if he's still in the running.
I don't care who they get, as long as he is capable of playing the part. Tobey Maguire was a good Peter Parker in the sense that he has such plain features; it was easy to believe he could be a nerdy kid (I'll use the word “kid” loosely here). But, what he had in looks, he lacked in what I can only label “moxie.” One of Spider-man's most entertaining characteristics is his ability to drop a witty one-liner in the midst of a superhuman showdown. Maguire did okay, but it sounded so unnatural for him to make jokes, the only exception being the line delivered to Bonesaw McGraw in the first installment:“Nice outfit. Did your husband give it to you?” But, at least he could emote...
That's where I see the plus side to these younger guys; maybe they'll exude some more energy and be able to bring that smart ass vibe that a teenage web-head should have. Maybe I'm just being a nostalgic child of the 90s, but they should force whichever one of these guys they wrangle to watch Spider-man: The Animated Series. I always thought Christopher Daniel Barnes perfected the delivery of the mid battle corny quip.
The most important thing, at least to the purist geek, is that the new guy has the right vibe that fans have come to associate with the character. And say no to Twilightization.