Second, the server load would multiply if every page that a browser has open on Perlmonks would reload all the time.

You're assuming that a refresh-every-n-seconds is the only way. What I was suggesting was more along the lines of only the chatterbox nodelet updating when the talk button was pressed. The chatterbox is used for more than just chat. Private messages and "you have a reply to ..." style messages are displayed here as well. It would be nice to be able to check the check boxes, hit the talk button, and not have the whole page refresh. In this style, I would venture to guess that the server load would be reduced, both from a CPU standpoint and a bandwidth standpoint. I could be wrong, though.