Actually, it kind of ruins everything. Why wouldn't everyone ask the same question you just asked?
He always fed off of biospheric energy before - which can only be obtained from select planets. Perhaps he cannot convert and store solar energy as well or as easily as he can with energy from planets?
He was trapped in the Cancerverse - that was collapsing in on itself. He isn't trapped there. He's dead. Or so we are led to believe. I don't think they will be back anytime soon.
I love Thanos more than anyone, but am very disappointed with how he was written in Thanos Imperative. He was way out of character. I hate to say this, but the whole arc was kind of bad, lots of things were not capitalized on like they could have been for some great story telling. It's like DnA were told "Marvel Cosmic is over. Kill as many as you can because all the titles are getting cancelled."
It seems you have more of a problem with the US than Cap. As expained, we are known as Americans. South Americans are Brazilians, Chileans, Argentinians, etc. Central Americans are Hondurans, Nicaraguans, Panamanians, etc. Up here, there are Mexicans and Canadians.
I don't think there is a person in the world who would hear the name Captain America and even have to wonder what country he represents.
If you are offended by Captain America, don't buy his comics
If you are offended by the United States (aka America), then don't buy our comics
@Caligula: While I agree wholeheartedly that they can indeed destroy planets (and no problem at that, especially at the end of the series), I am a purist. Manga only and no GT for me as far as continuity. :)