Poor Tim Cook had some mighty big shoes to fill on that stage today. Introducing the next magical Apple (Nasdaq: AAPL) invention isn't easy, and Steve Jobs had the presentation down to a science.

So Cook did a fine job in his Southern drawl, and there was nothing wrong with the presentation itself. But we were all left wondering … where's the beef?

As expected, Apple introduced a bushel of new software features, including a nifty voice-driven assistant. The iPhone 4GS packs the same powerful A5 processor as the iPad 2, the new camera is significantly better, and … well …

That's about it. Except for the speedy processor and better camera, most of today's upgrades will apply to older iPhone models stretching all the way back to the 3GS anno 2009. New iPhones also tend to sport sharper screens year by year, but there's none of that action today. Perhaps the bitter feud with Samsung put a crimp in Apple's high-quality screen supplies? LG Display (NYSE: LPL) and a gaggle of white-box Chinese panel builders might not have the cutting-edge power that Sammy holds. So just like I thought, there's nothing dramatically new about this new phone.

Anyhow, Mr. Market showed a clear disdain for the lack of truly big news, as everything was a simple next-step evolution from last year's model -- hardly a speck of fairy dust to be seen. During the presentation, Apple's market cap dropped by 6.3%. In other words, the lack of investable excitement destroyed some $21 billion in paper profits in less than two hours. That's nearly half of Hewlett-Packard's market cap or enough to buy Research In Motion twice.

Oh, boy. That hurts. That said, the iPhone 4GS will surely outsell the now-geriatric iPhone 4, which also becomes available in higher and lower-end configurations. The 3GS can now be had for free with an AT&T (NYSE: T) contract, and Sprint Nextel (NYSE: S) joins the growing army of iPhone sellers. So Apple continues to make a killing even as Google (Nasdaq: GOOG) tries to figure out how to squeeze cash from its hugely successful Android brand.

So if you've been looking for a buy-in opportunity on Apple shares, this might be it. If nothing else, you should add Apple to your Foolish watchlist and keep a close eye on what happens to this seemingly unwanted addition to the iPhone family.