So that image above? It's not real, so calm down. It's a 'shop that I'd love to buy if it were real, but one that fails as it doesn't have Yui's guitar. The image comes from this page that has you beliving that this product has been announced...until you scroll down. Mean.

The rumors are flying about anyway, but they're not very solid. This sounds more like some otaku's silly daydream. How would they do Mugi-chan's instrument? There's no keyboard controller! And "K" as in Konami? Yeah, I don't think so. Plus, after the domestic release of the craptastic Rock Revolution last year, I think I'd rather have someone else make my K-On! rhythm game. 

Regardless, someone is going to find a way to make this a reality. It won't be Activison or Konami, though. It'll be in someone's bedroom, on their PC. I'm calling bass.

[thanks, T. Miyagawa]