Well I was such a little fanboi that I’ve got leopard installed, things that I’m interested in:-

* RSS reader in mail
* spaces
* calendar App showing todays date

Things they didn’t mention which i think are good:-

* Tabbed terminal windows! Apple+T for a new one, Apple+}|{ to move between tabs

Aside from that, the coverflow-esque viewer to finder is quite nice – and pretty quick too. Admittedly, zfs is there – but no zpool create yet Think i’ll have to get the developer kit for that one.