The service, a combination of the Writely hosted word processor and Google Spreadsheets, has been launched and is being characterized by some, possible unfairly given the feature set, as Google’s answer to Microsoft Office.

Google is characterizing the software as complementary to desktop office applications, giving users an online collaboration space for their documents, and said that it plans to allow developers to extend it, as it has with several other software services it offers.

We definitely want to build out APIs, especially for the spreadsheets side, as spreadsheets are more data-oriented, but maybe also for he word processor, Google product manager Jonathan Rochelle said. People will be able to do mashups with our tools for other things, and not be stuck behind our dev cycle for everything they want.

Developers would be able to use the API to build software for pushing local content to the hosted services for collaborative work, then retrieving it later, by way of example, Rochelle said.

If I’ve already got data somewhere you can’t really rely on manual cut-and-paste to make it collaborative. Imaging pulling data from any application you’ve already got in use… you get that data over to the hosted app, make it collaborative, then bring it back… that’s what we’d like to enable at some point, he said.

While the announcement created a lot of buzz online, the two separate productivity tools, both of which Google acquired, were already available separately. Bringing them together is at first mainly about unifying the interface and file management.

Google chose the unwieldy Docs & Spreadsheets branding to avoid bringing up the O word in its branding. Comparisons with Office and OpenOffice are inevitable anyway, but not yet apples-to-apples.

Whether Google’s new suite will be a replacement for desktop apps really depends upon how it is used. Rochelle said that already everybody in the firm [Google] is using the tool.

Internal adoption has grown tremendously, he said. Internally, use cases are very board but focused on managing tasks and projects with anywhere from two to two hundred people.

In his own case, he said he might use a desktop office suite whilst commuting for a couple hours each day, but would then switch to the hosted service to collaborate on the same documents as soon as he gets to the office and gets online.

With that in mind, one could be forgiven for thinking that Google Docs & Spreadsheets can in many cases be used as an Office replacement, even within an enterprise. However, Google insiders have one thing other enterprises do not: support.

At present there are no plans to launch paid-for supported versions of the service, which would probably be a prerequisite for broad enterprise adoption. Indeed, Rochelle said that Google has not yet considered any monetization activities.

And while there’s no service-level agreement as such attached to the service, Rochelle said Google has a strong moral commitment to keeping it up and running.