A filler episode for sure - the most useful purpose of this particular story was as catalyst for getting the gang to visit Hollywood in the following episode, which served as the backdrop for Meowth's reminiscing - but as fillers go it was fairly entertaining. I like it whenever Psyduck is the focus, and I loved that it featured one of my all-time favourite pokemon, Raichu (the scene in which it danced with Pikachu was just darling), even if its trainer Katrina turned out to be a bit of a nobody in the grand scheme of things - she didn't even have a great deal of purpose within the context of the only episode in which she appeared. Arbok and Weezing's role in this episode was also gold - Team Rocket's pokemon are sweet when they get all emotional.
I take it that the movie's title "Pokemon in Love" was intended to be a spoof upon the movie "Shakespeare in Love"...the storyline being a thinly-veiled variation upon Romeo and Juliet (so much so that Misty even had to comment upon it), and all? If not, then it's only marginally more imaginative than what I hear was the title in the original Japanese version; that is, "Pokemon: The Movie".