Let me put this a different way. What players at the 3, in their prime, do you think could match up well with LeBron? I don't really think Bird had the athleticism to keep up with him, I certainly wouldn't take Havlicek over LeBron, and I think everyone can pretty much agree Pippen wasn't on the same level in terms of all-around game. Who does that leave? Dr. J and Elgin Baylor would be the two best candidates, but in both cases I'd argue that those guys were similarly talented scoring the basketball and rebounding, but not as exceptional passing the ball. In any sort of Dream Team scenario, whether it be 1992, 2012, or all-time, you have to figure that the floor is going to be littered with guys who can score the ball. Having an elite passer at the 3 is a huge luxury when everyone around him on the court can score. The only other guy I would even consider would be James Worthy, but he's basically in the same boat as Erving and Baylor and doesn't have quite the same statistics to back it up. At the end of the day I think that, at least on an All-Star team or better, LeBron in his prime is probably the best candidate to start at SF. I'm sure the nostalgics will find this statement ridiculous, probably in favor of Bird. Or Dr. J. I don't know.
I think at center the picture is less clear. There are obviously a huge number of people who would take Russell over Wilt, and with good reason. I'd take Wilt, but I don't have to make the argument for the guy who won all the titles. Kareem and Hakeem both have arguments against Wilt. I've already mentioned that I think Shaq would match up very well (incidentally, against other great centers I'd absolutely take Wilt. But the guy liked to play with power first, and Shaq has all his height with even more muscle. Doesn't have the offensive skillset, not even close. But I still think he'd really slow Wilt down). And what about Ralph Sampson before his knee problems started? There's a guy with the same kind of touch and court vision and skill that Wilt had, minus some power but plus 3 inches of height and a lot of wingspan. I'd say the highlight videos of Sampson in college and in the first few years of his NBA career match up very well with highlight videos of Wilt like the one's zbrent posted earlier. And if we're talking about how well guys transcend time, Wilt would handle the modern foul-happy NBA poorly compared to everyone else I've listed except Shaq - the guy only shot 60% from the free-throw line once in his career and had a career percentage worse even than O'Neal.
The point of all this is that the idea that LeBron is a unique talent and a top all-time player, particularly in regards to usefulness for an All-World caliber team, is not at all ridiculous. Nobody in history has stats that match up with Wilt's, but the competition at the time was much smaller and weaker than either the Dream Team or the 2012 team or any other all-time elite team. I don't hear anybody arguing that George Mikan is a Top 10 player in history. He was responsible for rule changes just as significant as the ones Chamberlain was. Until Wilt he was easily the most dominant player in history, but somehow because he's far enough back for very few people to remember watching him play firsthand there isn't the associated nostalgia and we don't have all kinds of people saying I'm a lunatic for not calling him one of the top 3 players of all time. The fact is that the scenario is the same - for most of Wilt's career Russell was the only other guy in the NBA with the size and strength to match up with him. Put him in today's NBA up against other 7 footers just about every game and he's probably the best center in the game, but maybe or maybe not the best player in the league.