Update 3 (A big one, so I'm posting it up top): There WILL be two Democratic challengers to Frank LoBiondo in NJ-2. Fairfield Township councilwoman Viola Thomas-Hughes and Henry David Marcus will compete in the primary. This now means that every Republican House member in New Jersey will face a challenger in November.
According to the Division of Elections, Gary Schiavone has filed to challenge Chris Smith in the 4th Congressional district. With about two hours left until the filing deadline, no Democrat has filed in the 2nd yet to challenge LoBiondo.
The GOP has failed to file challenges to Rob Andrews (NJ-1) and Donald Payne (NJ-10).
Update 1: Donald Payne (NJ-10) will have a challenger in the primary, and Michael Cino has just filed to challenge Garrett in the primary. Assemblywoman Oadline Truitt (D) from the 28th legislative district will face a primary challenge.