Keep the stock card and install the following WiFi kext.
I can confirm that it works, posting as I am with my stock AR9285 WiFi card.
The kext apparently comes from the 10.6.5 update beta, so updating to 10.6.5 when it's released in a couple of weeks would see it working anyway, but many of us use replacement WiFi cards so we wouldn't have noticed. So thanks to whomever it was who discovered this fix.
I now have a Snow Leopard running, 100% working Eee as it was shipped.
Best news ever for those of us not quite ready to switch our stock hardware out. Working beautifully...Thanks heaps.