I think that maybe joss was right about getting rid of cordy. While she was a good guy, she made everything seem safe and easy, and she held the gang together. Would Wesley have run off with Connor if Cordelia hadn't gone on a vacation? I don't think so. She had to be removed to make the cast seem more uncertain. After all, they can't have it too easy. The only thing is, I would have liked her to redeem herself first. She was a huge part of the Buffyverse, and she spent a whole season killing people. She could at least have said 'Oh my god, what have i done' when Jasmine was born, before she went into a coma.
Lilah was great, but her storyline had also finished. She had become an understandable character, and she and Wesley had begun to fall in love with each other. It would have got unbelievable if she had redeemed herself any more than that.
So, I think a change is a really good idea. Harmony used to drive me mad in Buffy, but in her new role she is actually being quite useful, and I really liked her in 5.1 & 5.2, so I'll give her a shot.
Eve seems kind of childish for a W&H liason, but i suppose they are trying to make her seem sweet and innocent so that they can do the whole 'appearances can be deceptive' thing again.
To tell the truth, I still trust Joss, and even if Eve and Harmony turn out to be really annoying, Fred will make up for them both, because she's absolutely gorgeous and very cool.
And if anybody from ME is reading, keep up the good work and feel free to bring back Alexa Devalos for some guest appearances!