techPowerUp! have a news story covering what's in store from the next version of ATi's Overdrive software.
ATI will introduce Overdrive 4 with the next Catalyst Driver scheduled in March.

Previously you could only overclock your GPU core with Overdrive, and only by a rather small amount.Now you can overclock both core and memory and the frequency range will be increased to 75% of the next higher class product.
[The story]