I don't think most of us have any idea on what market Apple is going for with the "rumoured" tablet. Apple tends to create a market for their product, rather than try to satisfy an existing market. They did it with the iPod, and they've done it with the iPhone. Who would have imagined having a phone as literally a portable computer, being able to easily (and very intuitively) browse the web (using a full browser and not just a mobile web browser, which is what existed before the iPhone), be able to do many other things, and finally, to have a marketplace (download apps right to your phone) with 100,000+ apps (in just over a year since the app store opened!).
A quote that Steve Jobs has used, and has integrated the philosophy into the DNA structure of the company, comes from Wayne Gretzky. "I skate to where the puck is going to be, and not where it is now" (I am quoting from memory, so I may have skewed the words a little bit, but I think you get the picture). Apple's plans with the tablet are not going to be to satisfy what we need now, but instead they will create a product that will create demand through its innovation, and it will create a whole new market. Of course, this plan may fail, but as I mentioned before, you'd be a fool to bet against Apple!
As to Apple store personnel, they have the "Mac Geniuses", highly trained people able to solve problems and have very good knowledge across the board on their products, and then you have regular sales staff, with some training, but by no means "Mac Geniuses". If a staff member told you that Apple doesn't have i7's in their machines, then it obviously was just one of the sales staff. Obviously their sales staff need to be trained better! I think they're still a cut above most other computer retail shops, but there's always room for improvement. Kind of like another Apple store salesperson who told you that you could install Mac OSX on any Intel machine (without hacking measures)! lol
As someone else mentioned, they've had i7's in their Pro desktop line for some time now, and introduced i7's in their iMac consumer line this Fall. The new Imacs are simply stunning, and are unibody aluminum (cut from one sheet of aluminum) just like the Macbook Pro's. There is no plastic anywhere on the body of the machine, they are sleek and elegant, and the display literally covers the entire face of the machine. They are absolutely gorgeous, and the display quality is unparalleled in anything on the market today (specifically the 27" LED). They even come with a standard wireless keyboard and mouse, increasing the minimalist footprint of the machine. I was in someone's house a little while ago and they had an iMac right on the kitchen counter. The machine takes up so little real estate, and the wireless mouse and keyboard only make it look even cleaner and uncluttered. Me wants one so bad!!!!! lol