I already have a decent WiFi router, and a WGRE (Range Extender) since some devices are a ways from the others. Also, Comcast Broadband -- not sure on the exact DL rate, but have never seen it slow even when all of our current devices are running (including home office server).
We're in the Trial Period with Netflix now, and have a (wireless) Toshiba (Tequila as we call it!!) laptop connected to a 60" Samsung via sVGA cable. Of course the picture quality is no better than the garbage video card in the Toshiba (way over saturated), but the stream is decent. Only used it twice now, and only noticed a couple of skips. Hopefully the Roku(s) will buffer a little bit and make it smoother?