You already know that VMware vSphere 4 saves you energy by running your workloads more efficiently. In addition to that, there is new aspect of vSphere that will directly save trees. With the vSphere 4 release, VMware is adopting a “no print” initiative for the technical documentation.
In the past, printed manuals have been available for purchase as part of a media kit. Going forward this will no longer be the case. Instead, the kits will include a CD-ROM with all of the documentation in PDF format.