Yesterday Brent Simmons released a public beta of his latest applications
NetNewsWire and MarsEdit:

Here are a few screenshots of NetNewsWire 2.0: setting up a smart list, creating a new search engine subscription, using the new embedded tabbed browser, a collection of built-in styles, and the activity window.
Here’s a screen shot that shows both NetNewsWire and MarsEdit—the Post-to-weblog button has been clicked in NetNewsWire, and the post has opened in a new window in MarsEdit. (More screen shots appear on the MarsEdit home page.)
NetNewsWire’s new features including searching, flagged items, persistence, per-feed refresh settings, new icons by Bryan Bell and Jon Hicks, embedded browser, smart lists, search engine subscriptions, script subscriptions—and more. The weblog editor was removed completely.