Some blogs you wait a long time for and here is one. Gray Knowlton, Group product manager in Office has started a blog. Gray is a top guy, funny, very smart and with lots of good perspectives to share. He is working on Office Open XML, the new open file format used in Microsoft Office, at the moment so his posts are sure to create debate. subscribe now is my advice! By the way here is a video including Gray where you might just notice a slight slurring of his words as I had to bribe him with beer.. :-)
His first post is all about the file size reductions you get from moving to Office Open XML. For some companies, the resulting cost reduction in disks alone can actually go a long way to justify the cost of the migration.