As for RSS, Google Base represents a kind of Confirmation. With Google's endorsement, RSS has now graduated from a rather obscure content syndication standard to the exautled status of the web's default standard for data integration. Google's endorsement should in turn push other competitors to adopt RSS as their data transport format and process of choice. This adoption will in turn force many of the infrastructure software vendors to enhance their products so that they can easily consume and produce RSS-based messages which in turn will further cement the standard.
RSS 2.0 spec by Google http://base.google.com/base/rss_specs.html
XML Spec by Google http://base.google.com/base/base.xsd
Seeing the Google Base RSS specs, to me it looks like it wants to control the whole data integration stuff on the web. But it's taking a different route from existing web companies. Most people when they want to launch a better classified service, they launch a new classified's website or a new job website. The key focus is a single service for the user. But Google Base I don't think is mean't for an individual user here (User will ultimately consume data but google is here focussed on integration rather than creation of data). Its perhaps mean't for companies and by integrating data from multiple web providers in a single shot, google can turn around the game.
Or perhaps the second approach would be to integrate Google Desktop with all such services. Create and Recieve data right from your desktop... But isn't then Windows Longhorn playing a similar game using a core RSS engine built within the OS!
