This decision has left me wondering, why would someone volunteer to decrypt their laptop? Isn't it the equivalent of telling the police where you hid the murder weapon? You can order someone to do it all you want, but the fact is I can't think of a reason the person would be motivated to give it up. In the end, I guess its the same as a murder weapon; you hope that the more cooperative you are with authorities the less of a sentence you receive as a result of the crime.
This portion of the case was really just a test to see if revealing a password *could* be protected under the 5th amendment, which it is not. I doubt this precedent is going to change much either in police work or in court cases.