Only a layman, but I would have to agree with _dexter_. When fighting viruses, there is such a huge overlap of tools with a recovery image that I don't see the point of distinguishing them, especially when you have a dvd room of space to add utilities.
For example, many malware and rootkits hide in such a way that you need mbr utilities, disk inspection utils, partition data and repair utils, undelete utils, registry utils, diagnostics utils, and access to backup copies (to repair damage). Then you need network and internet access to get further information or make backup copies or quarantine copies etc.
I think it's harmful to separate out the two, since one always ends up not having the disk one needs with the utility to completely solve a problem. A pe disk should be a swiss army knife, no compromise in generalizing tools that need to be specialized, but no compromise in omitting or segregating tools from one another. Completely self-sufficient and exhaustive, the be all and end all, perfection as man can know it etc.
However, no harm in a different forum if it doesn't result in a separate project, but just a subset of apps to deal with malware etc. It could be a project in the sense of a special folder in apps with more extensive or specialized malware utilities. but please not another project to build yet another type of pe disk--life is too short.
UPDATE: Of course, if you wanted to sell it to consumers, then you would want more of a turnkey/automatic system for detection and removal, but that would take a lot of work ("do no harm" would be a tough test) and be a very different type of disk I think.
My personal goal with such a disk would be to include AV tools that catch the most viruses and spyware when used in conjunction or right after each other with very few false positives, tools that work well for scanning the HDD and other hardware, any good tools that aid in repairing damage caused by viruses (without duplicates), and all of these allowing for definition updates WITHIN the disc, and as many tools as possible being run from the PE environment rather than from a separate GRUB option (though I have already included MemTest and want to include some other HDD tools like Drive Fitness Test just to be thorough). Oh yeah, and try to fit all that into a CD, just to deal with the older machines.
At this point it could hardly be called an AntiVirus only PE disc, but it is a repair disc and does act as a swiss army knife in a way. It would sure be nice to start all of the scanners automatically one after the other, create logs, and parse those logs after the scans are done to see how many viruses were removed, etc. Someone would probably have to actually program something specifically for this purpose.
I do have a project based on Win7RescuePE already that allows me to do most of this except that none of it is automated and I am usually faced with fixing windows from within windows, including running a second set of scans. That is what I want to try to avoid.