i don't have all that much of an opinion of edwards other than he seems to have a real talent to public speaking and talks a more populist talk than most politicians do these days. for a brief period in the primaries i was secretly rooting for him to win the democratic nomination, just to see him run circles around bush in the presidential debates. but other than his speaking ability i never really got that good of a sense of him.
as for what substantive policy priorities he will bring to a kerry administration? who cares. chances are he will be in favor of whatever kerry proposes for the next 4-8 years. vice presidents always have to toe the line for the president. bush senior was pro-choice when he challenged reagan in the republican primaries and coined the phrase "voodoo economics" for reagan's economic plan. he did a 180 on both issues from the moment he accepted his nomination for vice president. if there were any policy differences between kerry and edwards before today, they are probably irrelevant now.
all that vice presidents have to offer is adding to the nominees electibility. cheney was intended to reassure us that the boy-king will be under adult supervision, thus diminishing the public's unease with bush's lack of experience and apparent inability to handle the job. when gore was chosen it was partly to deflect from the draft-dodging charges that had already surfaced about clinton (it may be hard to believe now, but in the early 1990s, senator gore was considered to be a hawk).
what edwards brings to kerry is personality and the south. personality, i can believe. i don't think he's really bringing the south. (i think the south is the most pandered-to region in the entire country. and worse, ineffectively pandered to, because the south doesn't seem to notice the pander) common wisdom holds that it is impossible for a presidential ticket to win without at least one member at least pretending to be from the former confederacy. thus bush senior buried his connecticut roots and pretended to be from texas (claiming a vacant lot he owned in austin to be his home address). texas is a good one to fake too--since it's both south and west. perhaps that's why gephardt stayed on kerry's short list for so long--missouri is both south and mid-west.
but kerry's pick is from the carolinas. both carolinas, it turns out (born in south, now from north), but still strictly an east coast ticket. will this presidential election turn into east vs. west instead of north vs. south?
in any case, i am suspicious of the value of geographical diversity on a presidential ticket. how many people really change their vote based on where someone is from? i can't imagine voting for george bush, even if he were from pennsylvania. or chicago, my favorite place i have ever lived. if W talked like mayor daley, i still wouldn't vote for him. having a familiar zip code is simply no excuse for the war in iraq. i find it hard to believe where a candidate lives would matter enough to anyone to overcome any other reason to love or hate the candidate.
which brings me back to personality. unlike geography, i can believe that actually matters to get election. edwards has it, kerry seems to need it. so edwards is a good thing for the ticket.