After some days after the first setup, I can report some impressions on this Xobni plugin (http://www.xobni.com)
First of all after the setup process Xobni took some time to initializa, but given my huge mailbox this time has been ridicolously short. A fake? No... Actually Xobni started working immediately, with no glitches.
I have to say that this piece of software is really well designed, and given its speed (awesome) also the code must be great code. Great quality.
In the Outlook interface Xobni lives as a single new sidebar, and everything happens in there. This is a completely different choice from (for example) ClearContext. Actually the functionality of Xobni and CliaerContext are different, so given this, both choices are correct.
What I like most in Xobni? Search, for start. Fast (really fast) and complete. Then the information visualization, that collects in a very little space a lot of very well organized information extracted from my mailbox, contact list, and attachment collection. Please go here and take a tour of the screenshots.
But also "people navigation", or email analytics, or the threaded conversations are good ideas!
So as you maybe understood... I really like Xobni !!! :-)