Kasumi and Haruka feud. Who cares? Really. They are two characthers. Two DIFFERENT characthers. Yes, I am a Kasumi fan, but I will tell anyone, ANYONE - that Haruka is a bigger star on the show than Kasumi ever was.
Kasumi wasn't a big plot point, that's simple. She could of been kicked off like she did and there would be no plot-hole or any openings in her story. She wants to be a Water Pokemon Master...she can do that in her water gym, which she did.
Haruka has contests. This is the equivalent to Satoshi's badges. It is simple if she leaves and goes to Johto, her story will go on off-screen, but her story probably needs to be told on screen.
She is a co-star, I guess - at least from storylines, Satsohi's Brain is more important than the Festival in my mind, but her storyline isn't a C plot. It really is a solid B plot.
If Haruka goes, will I be sad? No. I hate her team. Simple. Her characther doens't really do anything for me, and if her story is left unfinished...I will feel a little twinged, but I will be more happy she's gone.
Kasumi, yes - I like her. I was sad she left. There is no reason why I should Haruka over her, because in my mind, I liked her team - personality and all that.
All-in-all, Kasumi...Haruka,
Hikari is now going to be in this mix, and I can't wait for a three-way feud of fanatics.