Google has been using it's blogger platform to deliver news about it's products and services to the masses. Including the multi-language blogs, there are about 76 Google blogs out there. But how often do they post? I went through each one (of the English blogs) and figured out the average number of posts, per month, that they have for 2007 so far. If a blog wasn't around back in January, I took that into account also.
The top two are the official Google Blog, and the Google Code blog, which makes sense as they are all encompassing aspects of Google. Following these are Maps and Adsense, two of Google biggest products.
This chart is live from the spreadsheet I made which you can view here