The best course of action now depends largely on the success of Apple's motion for an intervention. If that motion is granted, which is reasonably likely (though never certain), it will be time for Apple to clarify what support and coverage it gives to the sued app developers.

I know from at least one of them that he is NOT covered by Apple. If that continues to be the situation, the advice may unfortunately have to be at some point to sign Lodsys's license agreement if that results in dismissal from the lawsuit or helps avoid one.

For Android developers, the question is what Google will do. So far they say nothing and do nothing. If Apple's motion is granted, the question must be asked why Google doesn't intervene. One of the accused apps is an Android app ("Labyrinth for Android"). If Google doesn't protect Android app developers, they will also have to consider very seriously a license deal with Lodsys.

I have seen Lodsys's license agreement. I would recommend that many app developers share the cost of having it reviewed by a lawyer (rather than get into Patrick Igoe's claim chart stuff, which is neither convincing nor useful to those who can't afford a multi-million-dollar lawsuit over that question). If a lawyer agrees that the license agreement is reasonable, which in my personal opinion it is, then that's definitely better than going to court.

Patrick Igoe also came up with a "divided infringement" theory, which I rebutted on my blog. Apple apparently doesn't believe in his theory either, so why should you?