I like the 'real-time presence' aspect of it, and also how it aggregates and delivers to one central page everything from my continually updated Web 2.0 'empire'.
Flickr, friends photos, delicious, this blog, colleagues blogs etc.
However if I have one issue, and this might say more about me that Jaiku, it's that the levels of privacy seem pretty basic.
As I understand it, I can 'hide' my Jaiku from non Jaiku users, however any Jaiku user can see what I'm up to, where I am and who I'm talking with.
Fine fort inconsequential, fluffy stuff I don't mind people knowing.
But what if I was using it as a collaboration tool with a few tight colleagues, and we wanted to lock out prying eyes, (during a pitch for example?).
Doesn't look like I can do that.
So as a corporate productivity tool.
Sure I/we could use Basecamp or IM'ing.
But Jaiku has the versatility, connectivity and mobility I need.
Just not the security.
Just got an email from Jaiku re my problem.
Great customer service, and wonderful speed of turnaround.
when you check "Hide my Jaikus from the public", your profile (first name, last name, and buddy icon) remain discoverable at yourname.jaiku.com - but your stream of Jaikus, your location, and your list of contacts are not displayed publicly.
Only a Jaiku member that you have added as your contact can see your Jaikus, location, and contacts.
Any Jaiku member can add you as their contact (consider it a request - "please add me back"), but they will not be able to view your updates unless you reciprocate the add. This privacy model is similar to IM.
Hope this helps.