I believe that there is an extension for LibreOffice Writer to allow integration with Google Docs. I need to try it again to see how well [or unwell] it works. What I would like to see in LibreOffice is the ability to save directly to SkyDrive, DropBox or Amazon’s Cloud Drive.
I know the chances of LibreOffice making some sort of lightweight, online editor in the cloud are remote (although they should seeing as Chromebooks and iPads may be the future), but extensions like I mention would help bridge the gap. While I’m at it, I wish LibreOffice allowed one to download only Writer or the other apps. I never use anything but Writer and don’t want all the other stuff.