"Our goal was to first address Word, Excel, and PowerPoint. Integration with Office is an important theme for us, however,..." -DaveBlack
No one that I have ever worked with (at Microsoft or elsewhere) ever really "shared" a PowerPoint presentation, except to teammates and email was just fine for that.
However, OneNote and Outlook are both technologies that cry out for full integration. OneNote is more than just a section or a page... so don't consider it integrated until you can handle a full Notebook with Section Groups, Sections, Pages and subPages as a single OneNote compressed file. As it is I have to ZIP up a notebook section just to upload it to the Workspace successfully.
In my estimation, Microsoft Office Live Workspaces team did Microsoft and its customers a BIG disservice in putting Powerpoint integration ahead of OneNote, or ignoring one of the most useful products Microsoft Office has produced apart from Excel... but I understand that Customers Needs come far below what the Sales Team considers priority for its own use of the product. Microsoft is not alone in doing this, its just a vast disappointment to have to explain to friends and family how software projects are really prioritized and released and that sales have higher priority input into product releases than customers or product development do.
You can't honestly say that Office Integration is important unless you are talking about all of the Office 2007 Suite, instead of the Office 1995 Suite, now can you?
-Yew