The last couple of days have been Snow Leopard only. The Windows 7 hard disk is still gathering lots of dust in the corner.
Even though my Snow Leopard version may not be the final version, it feels solid on most fronts. Finder is even more intuitive. It starts to grow on me :).
I ordered my copy today. You can pre-order Snow Leopard in the Apple Online Store (upgrade costs around 29 euro/USD). With the free shipping it's a bargain (normally you need to spend >100 euro/USD for free shipping). This offer (free shipping) expires on August 27th 2009.