Our colleagues from Chiphell.com have managed to get their hands on ATI Catalyst version 8.1 for Windows Vista. The .inf file has revealed many interesting things such as HD 3870 X2, HD 3600/3400 series and HD 3650 AGP.
According to the inf file, we can expect the old HD 2600/2400 series to be replaced with HD 3600/3400 series based on the same RV630/RV610 chips. So, the HD 3650 AGP fact isn't that surprising, since HD 2600 PRO has AGP version. The new information is the ATI Radeon HD 3200 Graphics, which is based on the RS780 chipset, at least according to the .inf file screenshot.
The driver version is listed as 8.452, but it looks like Catalyst Control Center recognized the driver as 7.12, and not 8.1. Unfortunately, we can't say that this is reliable information, since .inf files can be easily modified, and CCC does state that it is Catalyst 7.12.
You can decide for yourself whether or not this is real. You can find the download link here.