Employee Weblogs Policy?

Even Bill Gates endorses weblogs for Microsoft employees, so do employers need weblog policies?

In this post Ross Mayfield discusses his frustration with the lack of a legal framework for innovative technologies:

" What's missing is a standardized weblog employee policy. Today, major tech companies like Microsoft and Sun are embracing external blogging and beginning to realize its benefits. Right now many companies are considering similar moves, but are held back by what they see as a legal grey area. "

Dave Pollard describes the benefits of using blogs in business.