The Kawaii, it burns into your brain...

Okay I'm a little late getting hit by this anime bullet train, but I think this is how our new computer generated overlords plan to do us in...
They have learned to sing in Japanese.

The opening salvo was Hatsune Miku and it looks like she has a nearly cult following as the image search on Google will show.
She was followed closely by the twins Rin and Len. That doesn't even begin to cover all the user generated content especially now that you can animate them yourself with a program calle Miku Miku Dance:

(Okay that's not the volcaloid's singing on that one, but the animation for something home made....

and the cover songs:

• The Proclaimer's 500 Miles
  
• Heaven Is A Place On Earth
  
• California Dreamin
  
• White Cristmas
  
• Phantom of the Opera jetsade heard this one when she was over a week or so ago, and seemed to be impressed with some of the more musically technical aspects of this one then I get but I like it... :-)
  

and now a couple have also started to learn English as well the latest being Megurine Luka. Seen here singing Amazing Grace: