- AT&T
Virtual Private LAN Service is evolving into the next "in" technology. AT&T defines it as any-to-any Ethernet that can be either metro or long haul.
VPLS allows enterprises to scale bandwidth and is a good fit for customers who require meshed connectivity and want to control and manage routing.
Download paper
VPLS allows enterprises to scale bandwidth and is a good fit for customers who require meshed connectivity and want to control and manage routing.
Download paper

This paper does an excellent job of describing VPLS (Virtual Private LAN Service) from a technical perspective, describing how VPLS "works," describing the benefits, and, most importantly, describing how where it does and does not fit.
Regardless of your choice of providers, it's an excellent resource.
I'm also most eager for you to add your comments about your experiences with VPLS - and how it has or has not been a fit for you.