Whilst I agree with you that McAfee or any other AV vendor for that matter would never play down the potential for malware to hijack a PC and steal souls, <sarcasm> and although AV vendors would never exaggerate the threat, </sarcasm>, the fact is malware is becoming more sophisticated.
All McAffee have done is predict, according to current trends, the methods that cybercriminals and malware writers are likely to employ during 2010. As a novice malware researcher, I have to have come to the same conclusions. So imho this is far from BS, but yes McAfee want to sell product.
PC's are now consumer devices, and thanks to MS a total ignoramus can use one, which would be a good thing if Windows and the applications it runs were secure. Consumers need to be made aware of malware threats and educated in how to spot and avoid them, not misinformed to the point that an AV suite will protect them. No AV solution is 100% and McAffee suggesting that their product will protect them *IS* BS.
I would suggest using a software firewall, not the MS bundled one, that will detect and prevent egress as well as ingress, but your average computer user is unlikely to be able to configure such software, or will just click yes to any prompts thrown up.
Expect things to get worse as more and more devices become network/Internet aware, code becomes more platform independent thanks to VM's and frameworks and more and more non technical minded consumers use such devices in ignorance of the threats.
In blissful ignorance, the biggest threat to computer security is the user.