It's not just that James is adding to his game -- which is scary -- but he looks good using both hands. Will he break out skyhooks in games, or is this just something that he's tinkering with? Looks to me like he has it down pretty good.
Regardless of how James uses the skyhook in games, it's impressive that he's still building his own personal arsenal. He's the best player in the world, and he just won a championship. James doesn't really need to get better, but he is. He's working to expand his game, working to become a more well-rounded player.
It's also going to be a good thing to have when he starts to age and that explosive athleticism isn't quite there anymore. James can go to the block and dominate a game there. This small addition might not pay huge dividends night-to-night this season, but LeBron is still working, which is impressive.