Google is an interesting company. Their recorded history is that they came up with a really cool product that outperformed the competitors by leaps and bounds, caught the eye of the masses through viral distribution and meteorically rose to be the free-food juggernaut that they are now.
The bad news for them (but good news for everyone else?) is that because of this recorded history, they seem to rely on what I call "Poltergeist Marketing" ("they're herrrreeee") for all their product launches since: develop an app, throw it out there and see if it catches fire. Unfortunately for them most (froogle, google base, etc.) don't.
This isn't really surprising though. Products for the most part don't sell themselves. That's the job of marketer's. When you hand most people something new, they have no idea what to do with it. They're lives are moving along quite swimmingly - what do they need your product for? That's the crux of marketing - giving people a reason to try something out. Plop, plop, fizz, fizz oh what a relief it is.....
This is especially true with an established, dominant brand (like Microsoft Office) that seems to be doing an adequate job. Pick a class of people (a segment) to market to, create a product that is catered to solve problems/ issues/ etc. that class, communicate the brand to that class.
So back to Google doc's. What problem is it solving? The fact that I can access my doc's from any computer. Ok, maybe. Never mind that I schlep my laptop with me everywhere I go. Then message that to me. Show me the use case. Show me the features that make this a better experience from that perspective.
Segment, differentiate, communicate.....MARKET! The poltergeist approach ain't gonna work. And, to be clear, despite your recorded history, poltergeist is not how your search engine succeeded...but that's for another post.