Update: I've just learned that owners can indeed restrict collaborators from inviting additional collaborators. Strangely enough, this feature only works for Spreadsheets, not Documents.
Google has combined access to its Writely word processor and Google Spreadsheets into a single dashboard - docs.google.com
I like Writely and Google Spreadsheets, and use both extensively. I like the integration that's gradually taking place across the various Google apps, and that's probably the biggest factor that's kept me using Google services instead of the offerings from 37signals.
However, both Writely and Spreadsheets need a whole lot more work in several areas... including encryption, access control and edit conflict resolution. I also miss the powerful formulas available in Excel, but I recognize most users would probably prefer a lighter, simpler spreadsheet application.
First off, security has a long way to go. It would be great to have encryption for these documents. And, as MAG pointed out to me, more granular access control - instead of giving everyone "collaborator" access with full capabilities to edit and share the document, we should be able to designate "editors" who can edit the document but aren't allowed to publish it or invite other collaborators or viewers.
Better visibility on changes currently being made by other people would be nice too - maybe different-colored highlights for the sections being edited? A couple of times now I've had edit conflicts with a collaborator making changes at the same time, and lost my edits. It was frustrating, but when you're talking on Gtalk while editing the document, the live collaboration is more convenient than the all-or-nothing lockout imposed by traditional check-in / check-out. We're working around it by using Gtalk or the chat window to tell each other which part of the document we're editing, but we've still lost a couple of edits here and there.
Google has a good track record of improving their products based on user feedback, so I'm looking forward to seeing what they'll offer next. I'd love to see Writely become the default text editor for Blogger posts, for example.
post this to del.icio.us