I'll second that. The deadlift is the maximum pull that the body can muster. As a lifter progresses one finds that it becomes very very taxing on the body's recuperative ability (CNS is included in this) - there is a big reason why Westside's Elite lifters avoid training the lift frequently. If you are going to pull heavy once a week and do some light pulls on another day you might get away with it.
There is a good program that has you deadlift 3x per week (Korte's 3x3) but also figure that it includes absolutely no assistance work and all you do is bench, squat, and dead every day 3x per week for around 8 weeks. If your max is somewhat respectable this program is a nightmare because you always have to pull last before you leave the gym. You can find Korte's write ups along with a lot of Louie's (WSB) in the Deepsquatter archives here:
http://www.deepsquatter.com/strength/archives/index.htm
Anyway, the point being is that you had better either be a beginner or you'll have to manage this very carefully if you intend to deadlift 2x per week. This is actually a really good reason to learn the olympic lifts (or even just clean and snatch pull variants) because it gives you a ton of possible pulling variants that are for the most part concentric only, far less taxing, and have a very solid carry over to the dead. Louie, WSB, tends to steer clear of them but this has never made sense to me as the same article that talked about the carry-over from the goodmorning listed the power clean, high pull, and power shrug along with it - it was written by Bill Starr BTW after he set a DL record without training it explicitly - he was an OL. With OLs you can pull mutliple times per week, acceleration is implicit, and you can redistribute your recovery away toward other lifts. Steering clear of the whole "teaching" argument by using clean/snatch pull style varriants this is pretty logical to me and it's probably the only thing that irks me about Westside.
Here's the original article:
http://www.americanpowerliftevolution.net/New Folder 1969/dlapproach1.html
Here's someone who recently did an OL assist program which lead him to a PR in the dead without training it. Do notice he had issues with locking out the heavier weight but also notice the one exercise he neglected was the dynamic shrugging (power shrug) which specifically overloads the top portion to supplment this:
http://www.ruggedmag.com/index.php?type=Article&i=15&a=9
Interesting stuff anyway. Good tools to have in the arsenal as the deadlift didn't earn the title as the "ultimate test of full body strength" by being easy to recovery from so train smart and use each tool to the best of your abilities.