The threat from the Wii U comes from the scary idea of a Nintendo console with 3rd party parity. With multiplatting existing equally across all platforms, the only significant differentiator (since non-software factors are fairly irrelevant) is first party software, where Nintendo commands an inaccessible lead
My pessimism, of course, believes that third parties will continue to scorn the Wii U because of the massive third-party conspiracy that exists, but the idea that threat could be enough to prompt Sony and Microsoft to move. Nobody wants to get caught with their pants down like Sony did early in this generation

Monster Hunter: pissing me off since 2010.







