Checking out the VMware Networking Blog, this caught my eye:

&quot;vMotion—a single vMotion can consume ~3.6Gbps with a maximum of two  running concurrently.

<!--more-->

FT can consume up to ~4Gbps but can consume much less if the FT  workloads are low. &quot;

The blog post is all about 10GigE, and essentially how awesome it is. It also goes on to provide some more information and suggestions about shaping the traffic-- the blog post can be found <a href="http://blogs.vmware.com/networking/2010/05/vsphere-loves-10gige.html" target="_blank">here</a>