Not saying that at all, Jim.
The significance of 2008 was an historic election with a Black candidate being nominated by one of the two major parties. You can't ignore the power of that -- he was the inferior candidate from the get go, but was marketed extremely well. You had the GOTV campaigns which targeted the Black communities, and parallel campaigns targeting minorities with the "support our guy, because next time it might be someone who looks more like you" message.
It was brilliant, actually, and why I call it exceptional. It won't be repeated, ever. Even if Hillary does become the next nominee for the Dems, you won't see the same level of excitement.
Aside from his election, Obama really hasn't turned out to be all that remarkable of a President. He's failed at bringing the country together, he's done nothing for the economy, and his foreign policy has been a disaster. Each misstep adds more fuel the fires of those critics who labeled him as nothing more than affirmative action candidate.
Because of that general ineptitude, Hillary will have a much harder time being elected. She can try to distance herself, but that only works so far. She was in a key position in his admin, and part of the reason foreign policy is so screwed up now.
Running on "they're the party of No" won't work out too well, either -- just about everything from the naysayers on Obamacare has come true.
The Senate vehemently opposed considering the GOP's "just delay it" and shut down the government over it. Then, when all the tin-foil dreams started turning into prime-time realities, Obama himself delayed it, essentially doing exactly what he refused to consider when it was "the other guy's idea"...
So... no, I really don't see 2014 being a repeat of 2008, nor do I think it will be horribly exceptional. It will be the typical midterm backlash against the party of an increasingly unpopular President.
Sure, the uber-faithful liberals will still turn up, but I suspect you'll see the Hope & Changers doing exactly what the Tea Partiers did to Romney in 2012 -- staying home. Their lack of enthusiasm cost Romney the election. This November, you'll see the roles reversed.