Please take the following with a grain of salt. These come by way of J-Hero; rumors and all that:
-Both Patoranger and Lupinranger will count as the 42nd Sentai.
-The two shows are both separate works, and the same show, with intersecting story lines that take place in the same world. The shows will air alternately from week to week, and when each reaches episode 20, the show will become one solidified story.
-The toy line will essentially be separate until this joining happens, with the 4th quarter toys able to combine and interact.
-One of the members of Lupinranger is actually an undercover spy for Patoranger. It is likely this cast member will be prominently featured on both shows.
My thoughts, if this is true:
-If the toy lines are effectively separate, there's a good chance both will utilize the same collectible.
-Even though the shows wouldn't officially join as one till the 40's (20 for each show), it seems like this hints at a lot of crossover.
-If this is true, the undercover agent is probably Patoranger Red. Like it or not, Red is the figurehead of the show, so having him around in the Lupinranger makes sense. It gives Red another form, but also lets the actor play an entirely different character if they so choose.
Again, GRAIN OF SALT!
-----Thanks to J-Hero for the info. PLEASE NOTE: The image on J-Hero's facebook post is not part of the rumor, it is an old piece of fan art-------