Minor League Baseball posted their list of top 20 Oakland A's prospects recently, and in that thread I asked John Sickels for his updated evaluation of Henry Rodriguez and Corey Brown, the two prospects the Nats picked up for Josh Willingham. They missed getting grades because his review of the Nationals prospects was posted before the trade (November 17), and the review of the A's prospects obviously occurred afterwards.
In response to my question Sickels said that he rated both Brown and Rodriguez as C+, borderline B- prospects. As a refresher, in the Sickels lexicon Grade B prospects have a good chance to enjoy successful careers. Some will develop into stars, some will not. Most end up spending several years in the majors, at the very least in a marginal role while Grade C prospects are the most common type (of ranked prospects). These are guys who have something positive going for them, but who may have a question mark or three, or who are just too far away from the majors to get an accurate feel for. A few Grade C guys, especially at the lower levels, do develop into stars. Many end up as role players or bench guys. Some don't make it at all. So both of these players are somewhere in the middle, with some development possible but by no means sure things.
There's good news and bad news in their grades. Sickels considers himself a tough grader and notes that "C+ is actually good praise from [him]." Obviously a borderline B- is even better. However, he also notes that a Grade C project in rookie ball could end up being very impressive, while a Grade C prospect in AAA is likely just a future role player - and Brown has already had one inglorious brush with AAA (although he lit up AA when he was sent back down).
Placed in a Nats context, these grades put Brown and Rodriguez at the back end of the Nationals top 10, judging by Sickels' list from November. To review, his rankings and grades were: (1) Harper - A; (2) Norris - B+; (3) Espinosa - B, borderline B+; (4) Solis - B; (5) Cole - B; (6) Ramos - B- (likes his glove, not his bat); (7) Ray - B-; (8) Burgess - C+, borderline B-. Rodriquez and Brown would slot in right behind Burgess, ahead of a raft of C+ prospects (Perez, Hague, Ramirez, Marrero, Lombardozzi, Meyers, Peacock and Morris). He has Maya as a C, incidentally, although he indicated in the thread that Maya's grade might be too low and will be reconsidered (he also indicated that the final grade for Espinosa may end up a B+ when he publishes his book.
You may compare with Baseball America's Top 10 Nats prospects, which came out right after the trade and doesn't mention the trade or Brown and Rodriguez at all.