Not that this is any of my business but why would you want to upgrade in the first place?
Lets think about this hypothetical situation. Suppose that suddenly, Futuremark went out of business. However, just before they did, they released a virus that would disable 3d mark and any relevant benchmarks. Now, suppose also that there is a Radeon Fairy. She knows you've been a good boy, buying ATI products and all. So one night while you are asleep, she decides to switch your 9700 pro to 9800 pro 256 mb (without telling you, obviously). Now, going about your daily activitites, how long do you think it would take you to realize this has happened? (Assume that in properties, SiS Sandra, etc, it still says 9700 pro.)