I was considering getting 16GB for the new MBP. I always have quite a few application open but nothing that is too power intensive. I do run an intensive trading platform though. Besides that I always have quite a few safari windows/tabs open, quite a few firefox tabs/windows open, mail, ichat, 2 dozen text edit windows, and open office. Please don't judge me on my lack of organization with web browser tabs, I literally have 30 open minimum at all times. I've noticed running all this slows down my system a significant amount. MBP 2.53 4ghz ram currently. I find I get the spinning ball quite often changing from one app to another or even when changing from one tab to another. I'm excited for the potential of 8GB ram... but would 16 GB make sense for me? Speed is probably the number one priority for me on my macs.