I see there are elections going on different SO sites and just wondering if there going to be any elections for SE too.
I would also like to know, whats the criteria for being a nomination.
All the SE sites don't get together and have elections at the same time; an individual site will have elections if it gets busy enough that it needs more mods. SO tends to have them at least once a year, and in this case one of their mods was hired to work at Stack Exchange, so they're down a person
The criteria for being a moderator is on the right side of the nomination page. SO is harder than most other sites; they require 3000 reputation and a handful of badges. For Sharepoint it's just:
any community member in good standing with more than 300 reputation