I am currently a long time Windows user. I have been researching and "tinkering" with Macs lately, and have decided I really want to invest in a Mac. I plan to buy a 2.4GHz 13" Aluminum MacBook with 4GB 1066MHz DDR3 SSRAM and a 320GB SATA HDD @ 5400rpm. As rumor has it, Snow Leopard will more than likely be released in 2009. Would I be able to upgrade Leopard to Snow Leopard in the future with the given configuration and not experience any performance loss? Any other suggestions for configurations would be appreciated. However, I'm not interested in the MacBook Pro, as it is larger (15" vs. 13")than what I desire. Thanks.