Hubris on All Sides
The plaintiffs have made some outrageous claims and tested the bounds of the legal system, but the people and institutions on the side of the defense are guilty of being equally brash and short-sighted. For example, some orders granting the defendants a dismissal for cause over the objection of the plaintiffs (a victory, indeed), have still allowed the plaintiffs to continue with the discovery process (whereby they demand the identifying information of the future defendants). In other cases in which the John Doe defendants have been severed and dismissed, the plaintiffs have already gotten what they wanted out of the case by the time that order occured.
If you have a homeowners/renters insurance policy, consider digging up its terms and conditions (its the thick booklet they mail you every time you renew). There might be something there which you could argue should cover you if you do ultimately have to pay the plaintiffs. (This is not yet standard practice, so I can't say whether anything will come of it, but has been discussed among attorneys in p2p defense cases)
Please note, this information is provided for purposes of background, and not as legal advice. If, after reading this, you have any questions or concerns, please feel free to call me.
There are a number of advocacy groups that are working to protect potential defendants in the new wave of copyright cases. These include the EFF (a fantastic institution to which, if you are reading this, you should very seriously consider donating) and EPIC. Although these groups do not have the resources to defend individual cases, they are a good resource to turn to for general news and information.
NOTE: I am not affiliated with or compensated in any way by either of these organizations.