One thing that's been knocking around the office for a while is some generic capability to add messages to any page. A shutdown warning could be one use of these messages.

I would like to see a "system alert" mesg and theme change that would go into effect before shutdown (colors change, BIG, AHOY! SHUTDOWN SOON MESG!)

As Sulka said, in the shutdown mode, users cannot login, existing sessions would be given a warning on the next page refresh.

And for sessions that do NOT come back to the server before shutdown ...(i.e. somebody hits "EDIT" but then goes to lunch break)

I have an app which has a Javascript timer on the page... that timer starts counting down upon page load, and ticks off the JSESSION time. At 5 min before end of session, a Javascript alert pops up to inform the user that the session will timeout in 5 min if they don't DO something.

At 0 min, another popup shows up which tells them the session has expired and they have been logged out.

Could combine this timer approach with XMLHttpRequest to check in with the server at say 10 min intervals (if the page is still up but idle, it could test for system shutdown status.)

As an ADMIN – it would be great to see the list of active sessions (with userid and uesrname and WHEN they will timeout.

That way if I am shutting down, I can see who's online and perhaps warn them via IM/Phone to please logout.

Might also be good to have the next page load have a javascript pop-up, or even interstitial HTLM page that warns users to logout in x minutes.

Cheers,
Nick