From what I read on Bulbapedia, the next episode is ANOTHER episode when Piplup gets all sad. If this last episode is all about Piplup running away and the group starts looking for it, I'm going to be very dissapointed. How many of those episodes have we had? We had the Gible one where Piplup runs away, we had like three when Meowth runs away, one when Aipom ran away (sorta), and quite a few when Pikachu got lost, which is close enough. Thats just a plot that they reuse every now and then. It's boring now. Hopefully, "Piplup's sadness" won't affect the plot too much. I want to see the three of them battle each other or something one last time. Then, Team Rocket could come and Ash, Brock, and Dawn could send out all of their pokemon to attack Team Rocket.
As far as Team Rocket's new design, I like it, but it's really just a recoloring. And aren't the grunts the one's who wear the black uniforms? I think Giovanni gives them the uniforms saying they got a promotion, but he's really just demoting them because he hates them.