This is exactly what they did with YW2 last year. Release two versions in the summer, and the third in December just in time for the holidays. It makes perfect sense, but it doesn't make this series any less milked.
On one hand, YW Busters is selling almost as well as a mainline YW, so in terms of short-term business this makes sense. But for the long term, I'm not sure if the series can survive much after next year. It'll be interesting to follow at least.
Good to see the 3DS getting another title for the holidays, though.