Facebook's newsfeed is a powerful lever to message users / fans, reach larger audiences and drive traffic. Like any marketing efforts, positioning and timing are important elements (a good reason to use services like Bit.ly and to carefully monitor referral traffic).
Publishers and application developers are well aware of this are getting more creative - and aggressive - with how they utilize the Facebook Feed. One of the most important changes is the inclusion of more imagery in the feed and through Facebook Connect - instead of publishing a single photo, developers like Zynga include multiple images to create a much-larger, more attractive one. Zynga, who is always at the leading edge of understanding and capturing virality, does this very well with their new hit (and fastest growing game yet): Farmville. The images are bold, great-looking and represent achievements related to the players' most recent activity.
Similar techniques are being applied by other application developers and to blogs (posts often have multiple photos). Considering that the feed updates in real-time and your network might post hundreds of times each day, standing out is as important as it is difficult.
Also of note, Rails Rumble competitor FastFeud.com employed similar techniques: when a user posts a matchup to Facebook, the feed contains an image for each item and a "vs." sign.
Member and designer Rob Abbott gives a tour of FastFeud and its Facebook integration: