Roku just announced that by June it will soon be introducing a handful of features that improve the Netflix streaming experience when using Roku, including the ability to do the following all within its channel UI: search the Netflix Watch Instantly library, browse and play content and add content to your Watch Instantly queue (here's a short company-produced demo video).
Currently users are first required to do all of these things online in their Netflix account, and then go to the Roku when ready to play their selections. This 2-step process has always felt a bit clunky to me and the new features obviously simplify the experience a lot. Roku spokesman Brian Jaquet told me he believes Roku is the first to offer the search function of the many CE devices Netflix is integrated with. I know Xbox introduced the browsing function last fall and I believe that at least PS3 and Wii (and possibly others) offer this as well.
Netflix has been hitting it out of the park recently with subscriber additions, with streaming an increasingly important drawing card. Things that Roku and others do that improve the TV-based experience are valuable, especially for more mainstream users.