This article, How Linux Could Overthrow Microsoft, in MIT's Technology Review caught me off-guard.
The article is a fascinating overview of the open source and proprietary software models. It appears to be well-researched and written, and makes a compelling case for open source:...For all its flaws, the open-source model has powerful advantages. The deepest and also most interesting of these advantages is that, to put it grossly, open source takes the bullshit out of software. Blog Post