We have DSL that is supposed to get us 3 Mbs, but I don't think I've ever actually seen evidence of any of my computers downloading at that fast a speed.
I have Netflix streaming set up on our wired desktop, as well as two laptops and our Wii, which all connect wirelessly. Streaming works pretty well (sometimes it will stop to buffer). Since your speed is almost double mine, you probably won't see any many buffering issues.
You may or may not be able to get HD quality video, based on bandwidth and screen size. I believe you have to be using a screen at 800x600 resolution (whilch should be the case), and the Netflix software must determine you are actually getting 5Mbs. Note that the Wii will NOT stream HD, because the Wii does not handle HD graphics. At least not at any resolution higher than 480p. I don't know about the XBox of PS3, though...