Earlier, Microsoft RSS Team officially picked the Firefox Orange RSS Icon to represent XML Feeds in IE to encourage consistency between browsers but today, I noticed a different design of the RSS icon in one the official Microsoft blogs.
The new Microsoft RSS Icon design (80x60 pixels as shown above) borrows the illustration and color scheme from the Mozilla RSS icon but adds a text "RSS" over it.
This icon graphic is actually enclosed inside a post on the Inside Office Online blog which incidentally, is about RSS feeds for the new Office Online website.