I've written about the desirability of shipping software VM bundles ('virtual appliances' or 'downloadable data center') and eagerly waited for the enabling technology. For a long time there was little incentive for a market leader like VMWare to cooperate with this scenario, because having a free "Acrobat Reader" for virtual machines meant fewer paid Workstation licenses (which was until recently the only option).
But with players like Xen and MS nipping at their lead, and virtualization-on-a-chip coming out next year, it's time for VMWare to establish themselves as the defacto hypervisor standard, in both API and disk formats.
And so, they now have VMWare Player, which is to VMs as Acrobat Reader is to PDF's - a free run-only version of the Workstation product. I've said before I believe this is really big for resource-starved open source projects in particular, because:
1) documenting the install process is a low priority.
2) supporting both *nix and windows is a drag both in skills and time
3) if they deploy on a free OS, they can distribute VM's for free
One of the first VM's I'd like to see would be a LTSP-enabled Linspire or Ubuntu distro, so you could download the VMWare player and another file and turn a school classroom or small business into a Linux thin client farm. But the possibilities are truly endless...