D3s - is it crazy to purchase one now...

I've been a canon user for a few years now, but nikon seems like it may be a better fit. I'm more interested in good low light shooting then high megapixels.

I've finally saved up enough to get a d3s.

with nikon's announcment comming on the 24th of august, is now the worst time ever to buy a d3s?

If a d4 is annoucned in a few weeks, how long it will take to get one? How much value will the d3s lose?

I know i should wait... but i'm tired of waiting!

thoughts?

thanks