Tim - if you don't take a rumour as gospel you can get insights into where things are going, plus taking into consideration past events/upgrades leaves things pretty obvious for things like the iPod and iPhone. You can't just go assuming every rumour is true, think about the tablet rumour going round, the likelihood is that Apple has a larger ipod touch (it makes sense with Apples push into movie retail) which they are internally testing, same goes for a leopard based tablet, it doesn't mean they will be released.
The macbook pros and the SD card rumour had been going round for ages, the upgrade to sealed battery on the smaller models was a given after the 17" and the release of non glossy displays on the 15" (and hopefully 13") as most 'Pros' were complaining.
I don't think of rumours as being accurate but they do give an idea that something might be happening, then its a choice of waiting. September is usually iPod month, so for the sake of waiting one month for either better value or cheaper price I'm all for waiting.