Windows live!

[Sten]

Originally Posted by Eleven

As far as I know it mostly runs in the browser, with requests sent for processing parts to be sent individually (so no actual data is sent through the internet/network).

Nobody will process his personal data with Live internet program since the program actually sends parts of the document to the server. (otherwise, how can you implement, for example, search-and-replace text processor feature with these Live things?). And these parts can (and _will_) contain personal information.
Also, there is no way to tell what data the Live program actually sends to it's server. At least it requires carefull investigation and there is no warranty the behaviour will not change with the next program update.

So, I think ANY program that operates on user personal data and have Live-internet design have no chances on the market.