In a Q&A over at the official Halo 4 site, franchise development director Frank O’ Connor said that a Halo 4 beta is not on their schedule. There are a few other interesting tidbits, you can head on over the site for full details.
In related news, Microsoft has just won the rights to the fake Halo4beta.net and has filed a complaint against Halo4beta.biz. Microsoft have warned fans to be wary of bogus Halo 4 beta sites. Seeing as how there won’t be any beta for the game, those sites will probably never go up again.