Difficult to say for sure. If you're talking make this trade pre-draft, NO WAY. 22 is still a spot where you can nab an impact player (Meriweather), or trade up a few spots to get the impact player (Warren, Wilfork). You just never know who's going to slip into the late teens and if you remove your flexibility before that you're going to kick yourself.
If 22 comes up, and the guys the Pats like are already off the board, then it's a great trade, and if there's a guy sitting there at 22 that Washington REALLY likes, they may even be willing to part with more to make it happen.