Horatio Caine (David Caruso) gets fired as head of the crime lab for getting WAY too personally involved in EVERY SINGLE murder investigation in Miami (and being a smug git). It wouldn't hurt to get rid of Delko while they're at it.
Calleigh Duquesne (Emily Procter) is promoted to head of the crime lab.
Connor Trinneer comes in as a hot-shot new CSI to fill her old position - we already know he can handle a Florida accent, right?
I'd really love to see these two play against each other, and I think the show would really benefit from an actor of Connor's calibre.