Yes, a VM will be started on the host that has sufficient resources to allow it to run. As VM usage varies over time, DRS will attempt to automatically balance VMs across hosts in the cluster.
For more specifics, i can highly recommend "Clustering Deep Dive" by Frank Denneman, Duncan Epping & Niels Hagoort. Best of all, you can get the PDF for free
Moderator: Moved to vMotion & Resource Management