"1. Will errai be supported by JBoss in future?"
"2. Can I use errai in Glassfish or anyother Java EE 6 server?"
"Do you have an example of how security will work?just a simple login dialog and few restricted pages based on role etc. May be something similar to JBPM console."
We have basic JAAS support, right now. But this system is extensible, and you can implement your own security scheme.