I guess it all depends on how you define middle. Guys like LMF and myself would say he abandoned the left but it all depends on where you're watching from. So many of his initiatives were actually bi-partisan or outright Republican ideals in the era before the mix of the tea party and the far right social conservatives managed to shift the GOP party focus.
You're absolutely right, it comes down to perspective. Personally, I think on issues like executive power and foreign policy; there's no question he's abandoned the left. The truth is there is very little difference among the two major parties in those areas anymore. The Bush doctrine and unchecked executive power have become the de facto "establishment" position. The only differences on foreign policy are semantic; do you yell at Ahmadinejad and then hit him with a stick? Or, hit him with the stick first and then yell at him. Romney and Obama don't have different positions at all on foreign affairs, they just emphasize inconsequential differences in the language each other use.
And to answer your call PMG; I'm not thrilled with Obama, but I'd vote for him based on economics alone. We have a lack of demand, and interest rates are incredibly low. Forcing the biggest employer to slash his spending now and make layoffs doesn't make sense to me. The private sector has to cut back during a downturn, it's the government's responsibility to fill that gap. And when they can borrow cheaply to do it, it doesn't bother me at all
That's my view, but I respect those that disagree. And there are many I'm sure.