I ended up installing firefox3 and flash10. While the flash tests from the adobe site work, and their flash 10 promo video works -- it doesn't seem to work well elsewhere. It doesn't work on youtube and on other *tube sites, if it does come up, it cuts out after several seconds.
*tube sites are about the only reason I contemplate using flash!
NetBSD 5.0 RC1
Firefox 3.0.5
Flash Player 10.0.0 d525