Devops is a new discipline that brings a mix of experience from the operational and development area. You definitely need to understand what the development team is doing but not necessarily be able to do yourself. You need to know as well hows live in the operational/admin team looks like ;).
This is a nice slide that brings some of the hot/buzz words you hear often when people talk about devops:
The full presentation can be found here: http://www.slideshare.net/mtesauro/devops-ci-apis-oh-my-texas-linux-fest-2012.