After a few minutes with the Apple Airport Express, Merrin and I were wirelessly connected to the new Canon photo printer and playing iTunes over our home stereo. The AE joined our existing wireless network and just started cranking away like a champ.
The Apple Airport Express is simple to use, works in Mac, Windows XP and shared environments, and makes something that could be difficult (wireless ap, print share, iTunes stream to stereo, etc) very, VERY easy. I'm talking "if you can put on a pair of shoes, you can do this" easy.
The Apple Airport Express is greatness. Plug it in, fire it up, and enjoy.