Re: 3D and sports:
I recently read an article about how 3D technology was going to revolutionize sports viewing, and my thought was how?. While the networks might talk a good game about how you'll be able to see the trajectory of the ball - whether it be a fly ball in baseball, a shot in basketball, a pass in football, whatever - I don't see that being much better than it already is. Truth is, as was stated somewhere above, people sitting in the stands at sporting events can't even tell the trajectory most of the time, and they're actually witnessing it live (go to a baseball game and listen to how many people scream in excitement when a high infield popup leaves the bat because they think it's a home run).
It's a matter of two issues - proper viewing angle of the play, and distance (camera view width) from the ball. Americans are used to seeing their favorite sports from a few standard angles centerfield behind the pitcher for most plays in baseball, with cuts to the fielder making the play once the ball is hit; sideline wide-angle where you can see almost sideline-to-sideline in (American) football; and high-halfcourt, wide enough to see sideline-to-sideline and nearly baseline-to-halfcourt in basketball. When TV networks start trying different things - like Fox trying to use the flyaround camera view from behind the QB for football - people revolt (XFL, anyone?). The reason those traditional camera angles above have been used for years is because they are the best angles to really see what is going on. You don't just want to see the QB or the batter, you want to see all the players involved in the play and how they are acting with relation to each other. But, by nature of what they are, none of these views really lend themselves to being improved by 3D, because they are either too wide-angle/too far away (football and basketball), or not an angle where trajectory would help (behind the pitcher in baseball). Think about how relatively small the ball is in basketball and football coverage. Would you really be able to pick up the fine nuances of a football pass arc, in the second or so that the ball is in the air, to tell where exactly it will land? Nope - and the truth is, most people's eyes, whether they realize it or not, shift to the receivers and defenders in the area and don't even watch the ball. And in the rare case where a long-bomb pass is thrown, and this 3D trajectory might be beneficial, where is the ball? Off the screen. We're watching the receiver and defender battle for position, and then the ball drops back onto the screen just before reaching the players. Unless you change to a diagonal isometric view of the field, you aren't going to really benefit from 3D at all.
So, IMO, the biggest battle that 3D sports coverage faces in America is not just getting people to cough up the extra money for the hardware, networks, and glasses, but getting Americans to accept completely new viewing angles for all the sports they are accustomed to watching. And Americans won't like that. There's a reason why the networks all save the isolation cameras and funky-angled views for replays only.
Supposedly the sport that benefits the most is soccer (football to the rest of the world). The extreme wide-angle shots, or even real-time camera zooms, that keep long passes on the screen, and the frequency of those long passes, could potentially give some added benefit to 3D viewing. In fact, I think soccer was the main sport that the article I read was discussing. But in America, how much soccer is shown? Nothing against soccer, but it doesn't have the viewership to support the money required for much of America to make the jump to 3D. I would suspect that, if soccer were really one of the only benefiting sports, it wouldn't be a very good business model for manufacturers of hardware, or cable/satellite companies, to invest in the techonology.
I can also agree that it might be cool having 3D for in-car views in racing. But how often are those views shown? And are you really going to buy a new TV, subscribe to a more-expensive TV package, and wear glasses, just for the occasional in-car view during the weekly NASCAR or Indy race? And they can't really use that view too much, because you can't see where many of the cars are, with relation to each other, from in-car cameras. And, as with soccer, this one sport alone would not be self-sustaining in relation to the investment required.
Long story, uh, longer
I don't think 3D will be worth the effort for sports.