Nintendo systems and how long it took me to get them:
NES - a few years
GB - many years
Super NES - eleven months
N64 - four months
GBC - within a month
GBA - the day after, evening
GCN - launch day, morning, hour after store opening
DS - launch day, morning, half-hour after store opening
Wii - ?
There's always been less time between the launch "moment" and my acquisition of one (with the exceptions of the Game Boy (I didn't get an original Game Boy, I got a Game Boy Pocket when Pok?mon came out which was WAY later) and the Virtual Boy (rented but never bought)).
This means that I should obtain a Wii on the morning of launch day (whenever that is), hopefully in less than half an hour to maintain the streak. I'm not aware of any midnight releases around here so it's all dependent on store hours, unfortunately.
A few more Nintendo systems and I'll have to start getting them BEFORE they officially come out. >_>
(I played some Wiis at E3 but that doesn't count, 'cause I played Japanese N64s months before it came out in North America. Glad to see that launches have gotten closer by region...and the DS came out in North America before Japan if I recall correctly.)
Working off the assumption that you'll want a Wii, how soon will you get yours?