From what we've heard so far, the new Opterons will use a Rev. F K8 core similar to current Socket AM2 Athlon 64 and Athlon 64 X2 processors, and they will introduce a new 1,207-pin land grid array-style socket in addition to a new model numbering scheme with four digits instead of three.
Along with the Rev. F core comes hardware virtualization support, and that seems to be the primary object of AMD's press release. AMD claims broad software industry support for the upcoming Opterons, citing an endorsement from VMware, which says the chips will "accentuate the benefits" of its VMware Infrastructure 3 enterprise virtualization software suite.