Andres Cantor and Manuel Sol. They have been joined by others on occasion, but Sol is the regular partner of Cantor. Cantor has been at the top of his game ... nothing new there, you already know what you're getting. Sol has been OK at color commentary, but as I say every Cup, I can't really be trusted to evaluate the color folks, because my Spanish isn't quite good enough to trust. Cantor's best call so far was probably Marcos Rojo's game-winner against Nigeria (Cantor was born in Argentina):
Sammy Sadovnik and Eduardo Biscayart. I'm a big fan of Sammy's, and he has had a fine tournament. There really isn't any drop in quality when Sadovnik takes over from Cantor.
Copán Álvarez and Viviana Vila/Claudio Borghi. I've seen them do a few matches, but they haven't made an impression one way or the other. Vila has been good ... both women commentators have been a pleasure.
There's also Horacio Elizondo, an ex-referee who comments on rules stuff and the like.
I only watched a few matches in English, and only saw the #3 team of Derek Rae and Aly Wagner. Rae has been doing soccer in the U.S. seemingly forever, and is a solid choice. Wagner has done quite well as color commentator.
The breakout star of the announcers has been someone I've only seen/heard on YouTube highlights. Jorge Perez-Navarro is familiar to Spanish-speaking listeners in the States for his work on MLS and Mexican League matches, but this is the first time I've heard him do English-language. What he's done in this Cup is bring the style of the Spanish announcing to English broadcasts. Not as easy as it sounds; even the great Cantor loses something in English. Perez-Navarro has been a delight.