You can subscribe to the Microsoft Excel Newsgroups by using the Atom feed from Google Groups. This means you can read them in software like Bloglines or Newsgator. As a matter of fact, all of the Google groups are syndicated:

Google – “To view a group’s feed information, go to the group’s homepage and click the “About this group” link under the title.”

Here are a few links to Excel Newsgroups in Google, look for the atom feeds in the middle of the page:
microsoft.public.excel.worksheet.functions
microsoft.public.excel.misc
microsoft.public.excel.programming
microsoft.public.excel.charting