My lovely wife and I went on Monday night to celebrate our wedding anniversary, and were pretty pleased. We both went with the RW menu. The ravioli are sweet (red-bean filled) and unusual. The edges of the pasta were a little chewier on both of ours than maybe they intended, but visually dramatic. I had the scallops, which were fantastic with an intense pea paste. B had the duck, the grand flourish of which was the bisteeya, a tiny little pie delivered in its own tiny little saucepan. I had the cheesecake for dessert, and thought it was superb; B, who isn't as much of a cheesecake fan to begin with, thought it tasted a little too much of cream cheese and too little of mango and caramel. She had the creme brulee, and felt that the filling tasted a little too much like vanilla pudding, but we both enjoyed the little hazelnut biscotti. All portions are in what may graciously be referred to as moderation; three plump ravioli, three big scallops, dessert you'll eat in miniscule bites to prolong the fun. We both had fancy virgin drinks that were tasty and in no way really deserve to cost $8 each, but you have to not get into that mindset or you'll find yourself over at Pinocchio's instead.
There are links to their RW lunch and dinner menus on the "Unofficial Guide to RW" site here: http://www.restaurantweekboston.com/
In brief, it looks like the menus for lunch and dinner are the same. The apps choices are Borscht or sweet veggie ravioli; the entree choices are scallops, lamb or duck; dessert choices are cheesecake or creme brulee.
Of course their menu is a bit more descriptive than I was here. ;)