I just read this interesting article about what a possible Google browser might look like (despite the fact they've since flat-out stated "we are not building a browser").

Since Google's new acquisition Keyhole was announced the other day, the article prognosticates a browser that ties all the Google services together into a "world browser".:

It would find pages on the Web, of course, but it'd also find the ones on my desktop (Google desktop). It would know about my email (Gmail). It would know that my own photos are categorically different from all the other jpgs on the planet (Picasa). It would let me browse the physical earth (Keyhole) and show on a map the documents that talk about any particular place (Keyhole + Google Local).

This would be undoubtedly cool, but so far there's been no visible effort by Google to make all their different products interact with each other (aside from your Gmail login working with Google Groups, and Bloggerbot in Hello).

I'm more inclined to go along with the view of this article, that Google's services are really all over the place, lacking a cohesiveness.
Maybe the plan behind the scenes is to tie them all together, but from the outside it looks like Google is split into loads of different teams all doing their own thing independent of each other.