Was there ever a generation that didn't cut with the old?
I dunno, Vista was kind of a downgrade from XP.
Seriously though, it's all marketing. I do think Apple gets carried away with the marketing terms. Magical and revolutionary? Really?
Like you said, though, the funny thing is that they just compare the new one to the old one. The tag for the iPhone 3GS is "The fastest, most powerful iPhone ever." No, really? I should hope your newest model is your fastest and most powerful. The same is true with the MBP models. "The fastest and most powerful MBP ever". You don't say? Guess what? My Powerbook 1.67 was the fastest and most powerful Powerbook ever when it was released.
One thing to note: Notice they never compare their hardware to competitors, only their own stuff. That is good marketing.