Answers to follow:..
1. What is the difference between JSR 168 and JSR 286 specs?
2. What is managed bean?
3. What is the difference between managed bean and backing bean?
4. If you have two same portlet instances in a single page, what are the things you need to consider in using java script?
5. How did you handle security in WSRP?
6. What are the performance issues you had in WSRP?