Probably, for the following reasons:
1. Better RAM management, compressed memory coded into OS X to prevent bottlenecks and slowdowns. Limited RAM goes further.
2. Better CPU management, doesn't run as hot and buffs out up cycles with intensive processes.
3. As mentioned above, still receives security updates.
4. Improved battery performance overall, due to CPU management.
With that said, you'll be fine on 4 gigs of RAM if you go to Mavericks.