I am intrigued by the new 13 inch MBA but the maximum RAM available is only 4Gb and is apparently not user upgradeable. I would love to buy a new MBA but only if I can be satisfied that its 4Gb of RAM would be sufficient to allow me to run Windows in VMware Fusion's Unity mode and simultaneously run several Windows apps and several OS X apps from the OS X dock. My current MBP is a Santa Rosa model so it can reliably use only 6Gb of RAM. That has been enough, however, for me to run as many Windows and OS X apps as I want at the same time. Does anyone here know whether 4Gb might be enough for that? Without some advance indication that there would be a high degree of probability that I could use a 4Gb MBA that way, too, I am unwilling to spend $1,800, plus tax on a new MBA, only to discover that it is unsatisfactory for my purposes. I would be grateful for any insights any of you might have.