That's probably because Lion isn't out yet or release. There no need to think about this. I do expect compatibility issues with the next major OS lion that many other applications other than games that works with current OS snow leopard won't work on Lion either.
This goes beyond the usual compatibility issues you see between releases. As I posted above, Rosetta is being removed from Lion.PPC versions will not work–– Blizzard would have to make an intel version. Which they have no plans to.