Obama picked Biden, a reasonable choice. Obama is an outsider and Biden is an insider, able to give Obama the kind of inside advice about how DC works that he will need should he become president. That Biden has particularly strong credentials on international affairs, an area where Obama's resume is thin.
Although Biden is being criticized for being not representing change, he is an "ideas" guy so he could still be positioned to represent new thinking.
Unfortunately, ideas are cheap in DC - implementation is what really matters. Is this Biden's strength - I'll leave that to long time Hill watchers to judge.
Another crucial characteristic for VPs is discretion (and remembering who is President.) Even disagreeing with the President in staff meetings can leak out. This may not be the mercurial Sen. Biden's strength. Of course, outspoken VPs might find themselves relegated to crowning produce queens in the farm belt. (Alben Barkley liked that job...)
Still, overall, a decent solid and serious pick.
Commentators keep noting that Biden takes Amtrak to get to Capitol Hill from his home in Wilmington. This is evidence of his common touch. He has also used his weight on the Hill as an advocate for Amtrak.
There are obvious positive spins to this - but there is the negative as well. He pushes for service that costs tax-payer dollars that benefits him. (He lives just far away enough that driving each way would be hassle.) Thanks to Amtrak he doesn't need a second home, but can work during his commute without having to pay for a driver. Good deal!
Maybe we should all try to do this (personally I am a fan of a solid rail transit network). But it could be spun another way, that this is a typical "liberal" program, subsidizing something that ends up benefiting the not-so-needy (sort of like rent control in Cambridge, MA.)
What about Hillary?
Apparently Hillary fans are mad because she wasn't even considered. But there was a simple reason for not considering her. A President does not need an ex-President hanging around the White House - no matter who it is. (Recall the abortive Reagan-Ford negotiations in 1980.)
That the ex-President in question is Bill Clinton might exacerbate the issue...