Congratulations, Mr. Jobs. You've done it again. You managed to dazzle the press and the growing cult of Apple ( AAPL) by giving them exactly what they were expecting. For weeks, even months, people have been talking about the release of an iPhone or an enhanced product to play digital videos in widescreen format. Keypads were worn out with predictions of which one would be unveiled. And lo, there came the revelation that Apple would offer both to the masses , and the masses were ecstatic. After dominating the market for digital-music players, Apple has boldly moved forward to plant one foot in the growing, if overcrowded, market for mobile devices, and the other in the still-developing field of downloaded video content. Wall Street stood and applauded, driving up Apple's stock 8% Tuesday while those of your new rivals Palm ( PALM) and Research In Motion ( RIMM) were down 6% and 8%, respectively. The shares were recently up another 4% on Wednesday, falling slightly off a new all-time high earlier in the session. It's pretty hard to argue against the view that you, Mr. Jobs, are standing at the helm of a company that sits on top of the technology world. What could possibly go wrong now? Well, actually, the fact of the matter is that there is one glaring vulnerability threatening to tarnish the shiny Apple brand, and that is ... well, um ... the thing is, Mr. Jobs, it's you.