On a side note, yes the 350Z is designed for long service intervals and to be honest 10,000km is not long at all, especially if you are using a good oil on a n/a engine, albeit a high revving one.
Currently, here in the states Mobil is advetising its new oil range, with 3 different oils with different service intervals, being
7,500 miles = 12,000KM
10,000 miles = 16,000KM
15,000 miles = 24,000KM
So I think the yanks are lazy, that and their fuel is shite, the cars run like a bucket of crap cause no one services them (I am just talking the tri-state area at the moment as I am yet to venture to far into other states).
So I am sure that 10,000km's will be fine, hey change it more regularly if you want, it cannot harm anything!!!