Computerworld UK Open Source Zone
Excellent open source news and features aimed at people working with enterprise solutions.
Yahoo! News - Linux/Open Source News
Up to date news about everything in the open source world.
News and features about open source also has very good coverage of Linux related news.
The largest repository and hosting service for open source projects.
Upcoming open source hosting and home of Google's open source projects.
Open Source at Apple
Portal of open source projects run by Apple.
Commercial Open Source
Blog run by Roberto Galoppini about open source for the enterprise.