"Nobody would care? Seriously? When BlazBlue was announced, besides the character designs (which people have come around on), people were damn impressed and wanted to play it. They obviously cared. I'm not ignoring the impact SF4 has on the scene (in terms of streaming videos and blah blah), but I don't believe this game's success nor any others afterwards is due to SF4. Especially considering SC4's success before it. Guilty Gear was successful as well in its time. If there was a new one with great online play, people would have been pumped too."
SC4 sold 2 million, but so what? As you said, it didn't cause streams of these big tournaments across America to pop up and it didn't cause a huge stick/part shortage either. It came and it went (really quickly, really). When you look at the rest of the fighting game release/related threads over the past few years on GAF, you'll notice they're dwarfed in comparison to fighting game threads over the past 7-8 months. Hell, the Evolution 2008 thread had like 15 posts total, the evolution 2009 hype thread already has *way* more than that.
I'm not saying SF4 is making all fighting games sell more, but I *am* saying SF4 has made people "care" more.