Massive, crippling recession in the UK, with unemployment at record high + console reaching it's mid-point in life, + summer = horrendous sales drop-off. It really doesn't worry me at all as a Wii owner and Nintendo fan.
Christmas should see some good numbers again, as it's simply such a popular Christmas thing, even more so than PS360.... plus Nintendo still have new colours, a price cut and even a redesigned Wii up their sleeves if they need to pull them out.