I am a switcher on an iMac Core Duo and have a Windows portable, but given how pleased I am with the iMac, I am anxious to switch in my portable life as well. I need to do light Windows use under Parallels (XP now and then Vista when it is released). Otherwise just need to to do the usual -- Office (mostly Word and Entourage), Firefox, iTunes, Skype, etc. on my portable. I do want this machine to last me awhile. Will I really be sorry not to have the Merom to run 10.5 and Vista, or should the Core Duo be just fine? Is Leopard likely to make all sorts of increased graphics demands?