Here's my thoughts:
Offense -
The Cowboys secondary is banged up, and has been a weakness for them for the past 2-3 seasons. As a result, I expect to see them giving our WRs extremely large cushions (a la Gregg Williams), and in response we'll see a ton of come back routes, crossing patterns & hitches. Grossman's ability to hit the WRs in stride will determine if these are 10-15 yard plays or 30-40 yard plays. This will set up for the out & up, which should be open several times during the game. Grossman hasn't yet shown a great ability to hit on the deep ball, hopefully he can turn that around this week.
As usual, Freddie Davis provides a huge mismatch against the Boys, who have been burnt for two TDs in two weeks by TEs. Fred should own the middle of the field this week.
The Cowboys run defense has been very solid in the first two weeks - the Jets simply could not move the ball on the ground (but LT was able to destroy them as a WR out of the backfield), and San Fran was held to less than 80 yards, but Gore managed a TD against them. I think a one-two punch of Hightower and Helu will be very important this week; keep the defense guessing. Plus, the Cowboys haven't played against someone as fast as Helu or as bruising as Hightower yet - hopefully the Skins can get the ground game going.
Defense -
Early reports were that Miles Austin would definitely miss this week, possibly being out until after the bye week. The latest is that he is now classified as "day-to-day," and may very well play Monday night. If he and Dez are both able to go, it will provide some nightmares for our secondary. Miles Austin has killed the Redskins since emerging for the Cowboys - 13 receptions for 184 yards (14.2 ypc) & 2 TDs last season. Dez Bryant has stepped up as the big-time WR the Cowboys expected when they drafted him; with our injuries in the secondary there is a lot of big play potential. Hopefully if they both play, their injuries will hamper them enough to give our secondary an advantage. If not...look out!
The Cowboys interior OL is not good - meaning Cofield, Bowen & Carriker HAVE to have big games. I expect a lot of DL stunts w/ ILB & SS blitzes. Landry is going to be sent early & often, with simple instructions: KILL. Kerrigan & Orakpo have got to dominate the Cowboys' tackles, so as to draw the RBs in pass-pro and open up the middle even more.
I'm not worried about the Cowboys running game very much - Felix Jones has a separated shoulder and is already Mr. Glass; he won't contribute much except on 3rd downs. The Redskins have been much better against the screen this year (IMO), which is where Felix would have killed last year's team. Even with a healthy Felix, the Cowboys have not been able to muster much of a running game the past two weeks. Also, if the Redskins offense starts clicking, they'll be playing from behind most of the game.
X-Factor (Cowboys):
Jason Witten. With their strength at WR, one has to assume Witten will be matched up against LBs all day. If their OL can keep Romo upright long enough, Witten may have a huge day.
X-Factor (Redskins):
Jabar Gaffney. The Cowboys will focus their coverages on stopping Moss & Davis, leaving Gaffney on a 2nd & 3rd CB all day. His precise route-running will give him the advantage all day, and if Rexy can find him he'll have a big day. 100+ and a couple TDs doesn't sound out of the question for Jabar.
Final prediction:
Yes, the Redskins haven't exactly been an offensive juggernaut, but I predict a final score of 35-28, good guys. The matchups are perfect for a high-scoring affair, just like last season's 30-33 loss. The Redskins were a dropped Santana Moss pass away from winning that game; this year Gaffney catches the game winner.