Shrook 2 is a next-generation news reader that offers advanced features not available to Mac users anywhere else. Some aren't available on any platform. It supports all versions of RSS, as well as the current draft of Atom. And it's all really easy to use, too. Shrook 2 is a free upgrade for users of Shrook v1.x.
NetNewsWire, the RSS reader standard on OSX has finally got some worthy competition.
This app has a great interface. It does not impact my machine's performance nearly as much as NNW. You can page around very fast in this app. It has "Smart Channel" capabilities that allow you to group entries and channels based on keywords and other factors. It supports HTTPS and logins, so its possible to support custom feeds like the Reputation Agent here at MemeStreams. It has that whole iApp thing going on, brushed metal and all. Its nice. If you use OSX, you should check it out.
Its also not without problems. It seems to be making Safari crash occasionally. There is no option to open pages in the background, as opposed to bringing the browser to the forefront. When you close the window, and later click on its dock icon, it does not bring back up the main window, only focuses the application. (Many apps do that) All my initial complaints are little things I can see getting worked out in a version or so. The key navigation seems to be missing ways to page-up/down an entry or visit a post without using the mouse.
All things considered, my first few hours with this application have been enjoyable. Aside from a post or two, including this one (twice), going into the bit bucket when Safari crashed. I'm forgiving to new apps. At $19, its also cheaper then NNW.
Update: Getting less forgiving by the minute. Might have to wait for the next version. Safari is either crashing or the viewer pane isn't working at any given time.