Will advanced viruses elude detection?

Tell us what you think about advanced viruses eluding detection from say antivirus software, as featured in the latest Internet Security Focus newsletter. Do you agree with the author of the newsletter that viruses will advance to the point that antivirus software will no longer be able to detect them? If so, what do you think the future repercussions will be? If you disagree with the author’s prediction, what are your reasons?