Saw something very interesting today... In setting up a little demo environment with some colleagues we only had a server with some very limited resources. In particular 8GB of ram and we needed to check out the latest version of VMware View. Once everything was finally booted up I found the virtual machines' balloon driver taking effect, memory sharing, memory compression, and memory swap on every VM. Things were a bit slow but perhaps we'll chalk this up to a test of ESXi 4.1 resource management and even better - nothing crashed :-)!