I don't see any leagal issues arising from the sale of Mopar parts. That seems a bit far fetched, would be like suing Autozone cause the big block rebuilt v8 you bought from them powered the car that you wrapped around a telephone pole, etc. Kinda like suing the highschool you graduated from or something cause you didn't score high on your SAT's!
And I don't see them voiding warranties either. They are going to make a killing on these parts as it is. The only way I could see them voided is if you do it yourself, or if it gets changed from a 3/36 on that part to the 12/whatever of the mopar part. If they do void warranties however, I expect you will see alot of people going aftermarket, and Mopar losing a assload of cash in potential sales. Would I pay 10 or 20% more if a part doesn't void my warranty - hell yes! And I think Mopar is smart enough to know that, and that the extra 10,20,30% more they charge will easily cover any additional repairs they have to do under warranty, if any. Sides, I don't see them offering anything that's going to blow motors, these guys have done thier research. Mopar is a subsidiary of DCX too, and in the end I beleive any money they make from parts will easily cover any added warranty work, it makes good business sense IMO.
Jon