Looks like a robust roasted porter to me. Something like:
5.5 lbs DME
0.5 lbs Chocolate Malt
0.5 lbs Roasted Barley
0.5 lbs crystal 80
0.5 lbs crystal 30
0.5 lbs flaked oats
1 oz Centennial @ 60
1 oz Fuggles @ 30
Windsor Dry Yeast
Mash the grains, add the DME...yadda yadda...
I'll throw this into BeerSmith when I get home and give you some more exact #s, but this should be pretty close for a good strong roasted porter with a dry finish like a Guiness. If you perfer a thicker/sweeter finish, just use Nottingham or S-04/S-05 yeast instead, but most commercial styles are on the dry side.