Hello,
I have been in USA since 2003 and now I am in H1B status from F1 status. I know after 5 years you are taxed as a regular US Citizen, i.e. Treaties, using 1040NREZ and filing 8843 is out of the window. I support my parents who reside back home, can I claim them as dependents on my return from now on even though they do not have SSN.

Any help would be appreciated.

Sorry, but for a foreign national to claim his/her parents as dependents, the parents MUST reside in the United States.

If you are on F1 since 2003, then you will file resident tax return for 2008. Read about F1-H1-B tax filing: Your U.S. Tax Return: The U.S. Visas

If your parents are from Mexico or Canada, then you may be able to claim them as dependents. See Aliens - How Many Exemptions Can Be Claimed?

Agreed! Forgot about the exception for Mexico and Canada.

Glad to help.