The 22 year old Ramos happens to be the Twins #2 ranked prospect and #58 overall according to Baseball America's rankings. Here's more on Ramos from Nats Insider's Mark Zuckerman,
A native of Venezuela, he is a career .284 hitter in parts of five minor-league seasons who appeared in eight big-league games earlier this season and went 8-for-27 with three doubles.
Pitcher Joe Testa has a combined 2-5 with a 5.86 ERA for Class A Fort Myers and Double-A New Britain this year, but has a career ERA of 3.33 across 3 minor league seasons.
This trade seems pretty fair for both teams as the Twins now have a set-up man and closer in former Nationals John Rauch and Matt Capps, while the Nationals might have finally gotten their catcher of the future since Jesus Flores has not proven he can stay healthy throughout his career.
For more discussion on the story, head on over to Federal Baseball.