On July 5th Reuters ran an article that included quotes from Nikon's Senior Managing Director, Makato Kimura. The key bit: Kimura-sama says April and May 2006 sales performance puts DSLR shipments up 35% over those same months last year, which puts them ahead of the current forecast growth estimate they made of 30%.
Personally, I'd caution against reading too much into that statement. First, these are sales from Nikon to distribution, not distribution to customers. Second, the impact of increased competition won't really be felt until the second half of this year (note that Sony didn't announce the Alpha 100 until after the period Kimura-san is talking about).
Much more interesting was the comment that the Thailand plant (D50, D70s, D200) was running at capacity, which would tend to argue against another consumer Nikon DSLR being introduced any time soon.