So I have a friend who wants to sell me a 13" Macbook Air Late 2010 1.86ghz and Speck Products Satin Black Snap on case, in case sleeve, a full coverage invisible shield for $1000. It's still 2gb of ram though... The only thing that scares me is the new macbook air that will be coming out soon. Is this too good a deal to pass? I don't need an air right now, but I was planning to get one with 4gb when the new one came out. Is it possible to upgrade to 4gb later?