The suits are based upon general functionality, not copying specific lines of code. So, Open Sourcing the code wouldn't expose HP to any more lawsuits. The Open Source community wouldn't have much to be afraid of, as Apple would only have a case against HP for distributing the tablets in the first place. Of course, none of the patents are valid, but I get your point about just getting hit with a multi-million dollar suit being to rich for just about anyone's blood.