I'm trying to decide whether or not to sell my MacBook and get the 13" ultimate model of the MBA. My MacBook has a 2.4 GHz Core 2 Duo, 4 GB RAM, and a 60 GB OCZ Vertex 2 SSD. My gut tells me no, that the MBA would not really be an "upgrade" (except for case design and hard drive space obviously) but is there something I'm not considering?