McAfee defines unique as a piece of malware "we had to write a driver for."
The criminalization of malware -- its makers want your money, and want to keep themselves as hidden as possible while they're doing so.
The fact that malware detection rates are keeping up with the onslaught is a good sign: but only if you and every one of your employees, vendors, partners keeps up with the latest virus definitions, patches and other defensive measures.
Understatement time: The malware makers aren't slacking off, and may indeed, thanks increasing organization and the use of automated tools, be only beginning to accelerate the volume of crimeware they distribute.
They're not going to relax their efforts for one minute (every one of which sees four new pieces or malware, at current rates) and neither can you or your business.