Energy savings, etc... I'm typing this on my late 2008 MBP awaiting my new i7 MBP to use as my daily workhorse. Current rig has 7200RPM drive. I also have a MBP AIR.... So granted the SSD is blaxingly fast and once apps are open, it's all one and the same to a degree, what's the additional benefit of SSD. I'm debating whether to spring for a Intel for the OS/APP drive. In my world, since I do constantly have a VM open, I do believe there are benefits to this . But on the OSX side of the house, just short of fast OS boot (which I hardly ever need unless System Updates requires a reboot), my apps are generally ~open~ in general.