Bruce Byfield has interesting article in Linux.com featuring hands-on comparison of four on-line wordprocessors: specifically ajaxWrite, ThinkFree Online, Writely, and Zoho Writer. I do not 100% agree with all his conclusions, but it's interesting and worth reading if you are exploring these tools. I am certainly staying with Writely, right now I am using it on daily basis. Combination of WriteRoom for off-line concepts and "thinking phase" of writing and Writely for on-line editing, adding links, etc fits ideally my needs.
Regarding spreadsheets, Excellery seems to be addressing the shared pain of all on-line spreadsheet - which is need for connectivity. They claim that you can work on-line or off-line and synchronize. Sounds pretty good - I'll give it a try !
Good choice, guys !