Edit: Ok, after looking into this a bit more, I'm guessing that this is something related to the ATI Multimedia Center software. If you go to ATI's site, there's a download link for it but it says you have to have an origial install CD to be validated for the download. It may be that the partner cards don't come with this(?), in which case you'd have to buy it for $12.99. I've never used that software so I really don't know what it's needed for, but maybe it will be required for some of the upcoming AVIVO features.
ATI's Multimedia Center Software isn't bundled with BBA X1800 XL. which undoubtably does support AVIVO. Its always been a free download, only the DVD decoder part requires CD verification. Sapphire cards bundle Cyberlinks PowerDVD decoder, BBA distributes an OEM, less featured version of the same Cyberlibnk Decoder software.
Clearly the Sapphire box shows AVIVIO support, and entering "AVIVO" into Sapphire's site search engine brings up x1600 cards touting AVIVO support, every review I've read shows AVIVO support for the Sapphire cards as well.
There are 5 AVIVO components, you don't need all of them for "AVIVO". The tech includes hardware and software features, so its possible that "AVIVO" support isn't dependant on supporting every feature for a vendor to "claim" AVIVO support.
The bottom line: Don't buy hardware for a specific feature without that feature being supported. If specific card features are important to you, you really should wait untill it is available, supported and reviewed before jumping in, otherwise you could be setting yourself up for disappointment.
You shouldn't have long to wait for more details I wouldn't think.