The Company of Heroes 2 Closed Beta is current not closed at all, since Sega has announced that anyone can get in simply by 'Liking' its Facebook page.
In exchange for clicking the enlarged 'Like' button on the game's official FB profile - and the inherent free advertising - Sega will give you an access code for the "second phase" of the currently-underway beta, which kicked off earlier this month.
The codes are redeemable via Steam, so you'll need to have the free Steam client installed to play.
The beta features multiplayer and skirmish gameplay, with access to six maps and the ability to team up with friends for battle against others online or against AI. You'll also get the first 40 levels of progression, and customisable loadouts.
Sega has confirmed a Company of Heroes 2 release date of June 25, 2013 in North America and Europe.