I just measured the SG of my MLK schwarzbier (brewed at the MLK brew-in on 1/18/2010). It's at 1.017 from 1.055. Here's the recipe...

Recipe: RSF Schwarzbier
Brewer: Mark Rogerson
Style: Schwarzbier (Black Beer)
TYPE: All Grain

Recipe Specifications
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Batch Size: 12.00 gal
OG: 1.055 SG
Estimated Color: 18.8 SRM
Estimated IBU: 27.1 IBU
Brewhouse Efficiency: 87.00 %
Boil Time: 60 Minutes

Ingredients:
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Amount Item Type % or IBU
16.50 lb Pilsner (2 Row) Ger (2.0 SRM) Grain 80.49 %
2.00 lb Vienna Malt (3.5 SRM) Grain 9.76 %
1.00 lb Wheat Malt, Ger (2.0 SRM) Grain 4.88 %
0.69 lb Carafa II (412.0 SRM) Grain 3.35 %
0.31 lb Black (Patent) Malt (500.0 SRM) Grain 1.52 %
2.00 oz Mt. Hood [5.00 %] (60 min) (First Wort HoHops 15.7 IBU
1.00 oz Hallertauer [4.50 %] (60 min) (First WortHops 7.2 IBU
1.00 oz Saaz [4.00 %] (15 min) Hops 3.2 IBU
1.00 oz Saaz [3.10 %] (5 min) Hops 1.0 IBU
1 Pkgs Bavarian Lager (Wyeast Labs #2206) Yeast-Lager

Mash:
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30 min @ 147
30 min @ 152
20 min @ 168

It'll probably drop a bit more as I do a diacetyl rest, but I won't sweat it if it doesn't. At 49°F, it was fermented at the low end of the range for that yeast, so far.

Believe it or not, I raise the temp by turning up the thermostat on the refrigerator and letting nature take its course.

I do not test for the removal of diacetyl. I do test for the presence of it with my nose and tongue, but not until after I do a D-rest.

I do a D-rest on every lager I make because of the ridiculous amount of it that was in the first lager I made. Since then, no D-problem. I have no idea if it's always necessary, but I always do it.