I used Google as a Platform when I was doing my social media marketing business. It gave me a ready to go platform to collaborate on without building something from scratch.
I am enjoying trying to retrofit it to work as a solid business platform, because of this I am looking at it in some very different ways.
If you look at it from a high level you really see a lot of pieces coming together as a robust toolset to operate in the clouds.
So I start with Google Apps for My Domain, it gives me:
It gives me a way to store my information, communicate and publish information both internally and externally. It gives you a great start.
Then I link up my paid domain account with a free Google Account which gives me more tools in the Free area (a little disconnect here).
I add in Google Reader and Google Bookmarks.
I can use IGoogle and Google Gadgets to create an interface that can be used internally and external by using existing or developing widgets.
I can share information and access with people internally and externally.
I am given a pretty robust communications platform using email, talk, and SMS.
I can access most of my information using Android and other mobile tools.
I can publish different types of information using Google Docs, Google Sites.
You are given a business layer for developing custom systems using Google App Engine. And also a library of code to work from or store your open source libraries at Google Code.
Then you can process payments using Google checkout to make all your money.
There are definitely lots of gaps in there. However you start seeing the vision come together if you squint your eyes.