Hi Subodh,
What you mention is possible and it's done a lot I'm sure. For traffic to be accelerated there must be a WAAS device at both locations. Sites that don't have a WAAS device will ignore the TCP option bit that the WAE's use to identify each other and traffic will run unoptimized.
If you have more questions on WAAS I suggest posting your questions to the Application Networking form. There are some very bright WAAS people over there.
HTH.