Reeder, a popular Google Reader client on iOS, is now out of beta and available on the Mac App Store. While the beta version of Reeder for the Mac was free to test, the 1.0 release will set you back US$9.99, more than twice the price of the iPad version.
That $9.99 offers syncing with Google Reader (which you can set up for free), plus integration with Readability, Instapaper, ReadItLater, Pinboard, Delicious, Zootool and more. The app has a customizable, multi-column interface that's superficially similar to the iPad version, and Reeder includes gesture support and customizable shortcuts.
If you read a lot of news on your Mac, Reeder definitely looks like a big step up from reading RSS feeds in Safari or Mail. We've got several Reeder fans on the TUAW staff, and one of them will likely be providing a full review of Reeder in the near future.