Summary
This marks the second straight year that the Astros have taken a Puerto Rican high schooler in the top ten. Last year, it was middle infielder Enrique Hernandez and this summer, it's catcher Roberto Pena. He's considered the best defensive prep catcher in the draft, but his bat does not project well.
His defense is for real. With his skill set, he can absolutely shut down another team's running game. He's got a great arm and, more importantly, great feet. That may come because he is a former shortstop that has made a successful transition behind the plate.
His profile reminds me a bit of Federico Hernandez, who's currently sitting in Lancaster. Both are defense-first players who will go just as far as their bats will take them. I don't know what it says about Pena that Hernandez is still in High A ball.
Floor
If the bat is not there, his floor is pretty low. I could see him turning into a Jonathan Fixler or Brian Esposito, maintaining depth in the organization while helping to mature pitchers. The other downside is that as we wait for the bat to develop, he may lose some of his quickness and arm strength, thus cutting down his best tool a bit.
Ceiling
Unfortunately, unless he develops a lot with his bat, his ceiling is probably Humberto Quintero. Or, as some of the commenters pointed out, Tony Eusebio. He'll need to hit more than he currently profiles to make it up the ladder, but he just adds another reliable catcher to the Astros ranks.
Will the Astros Sign Him?
Looks like it. Pena went right around where he was expected to be drafted. He is currently not committed to a college and doesn't really have the leverage to turn down an offer. Sure, he could try to go play junior college ball somewhere, but I doubt he does that. Instead, I'm sure he'll opt to sign early and be assigned to the GCL Astros.