Companies tend to allow journalists to publish the information shortly before the actual event sometimes through a press release. It's a common practice in an attempt to get more coverage for what the company deems good news.
i just bought the 2.4ghz aluminum macbook and am shopping too. i made the mistake of buying cheaper ram years ago with my quadra 840av and had the machine play chimes of death when i was on deadline for submitting some remixes.
after that i've gone with what apple's recommended and it's been samsung for me.
i may just have to wait.