The offer expired on April 30th - http://vmware.com/vmwarestore/esxi_management_kit_promo_terms.html
You would basically get vCenter Foundation and 3 agent licenses. Your 3 ESXi hosts would be limited to 2 CPU sockets and vCenter foundation is limited to managing one 3 hosts (you have to upgrade to the regular edition to do more hosts). With enough CPU and memory you could run 192 vCPUs per ESXi host.
basically, yes. But as Dave pointed out, the promo is over. I'm glad I picked it up though, it was a hell of a deal.