It's not. From Media Matters:

Failing Upward: Breitbart To Be Featured in ABC's 2010 Election Coverage

October 29, 2010 5:33 pm ET by Matt Gertz

Media Matters has confirmed that noted propagandist Andrew Breitbart will provide analysis for ABC News during their election night coverage.

After Breitbart's BigJournalism.com website reported that Breitbart would "be bringing analysis live from Arizona" for ABC, Media Matters confirmed his participation in a town hall meeting anchored by ABC's David Muir and Facebook's Randi Zuckerberg that will be featured in the network's coverage.

Asked about Breitbart's history of unethical behavior and misinformation, ABC News' David Ford told Media Matters: "He will be one of many voices on our air, including Bill Adair of Politifact. If Andrew Breitbart says something that is incorrect, we have other voices to call him on it."