The core count of today's Opteron processors is at 12 but that number will increase and reach 16 in 2011 and 20 in 2012. AMD's first 16-core processor is known as Interlagos and will be introduced in 2011, while the 20-core beast is codenamed Terramar.
Terramar will be manufactured on 32nm process technology, feature enhanced Bulldozer cores, quad-channel DDR3 memory support, PCIe Gen3 I/O, and is set to be part of AMD's 2- and 4-way Socket G2012 platforms.
The growth in core number will not transcend to the desktop segment, unfortunately, so we'll have to 'settle' for 8-cores in 2012. At least from AMD.