Dual Boot FUD
Easier? How? Easier as in, don't need to port your app to Mac OS X now?
Dual-boot is a dual-edged sword. The Mac could effectively be dead for gaming. Why would anyone spend the money to port a game to the Mac now when you can just say "install Windows". Anyone who's spent enough money on a Mac good enough to run new games on is probably not going to flinch at spending the money to install Windows to play games.
Ditto for plenty of other Windows apps.
This was the standard answer when OS/2 users asked for a native version... actually it was worse on OS/2 because you could run Win16 apps in OS/2 through Win-OS/2. I'm sure there will be a free VirtualPC/VMWare-like app for Mac OS X/Intel, and unfortunately I think it'll work very well, and be very fast. This could be bad for the Mac. Honestly I think it doesn't help that OS X won't run on other manufacturer's PCs, because it means the potential market for OS X apps will STILL be limited to those who buy Apple PCs, instead of potentially the entire PC market.
There used to be a small but growing market of people who liked to spend money on quality computers and software but couldn't run Windows software, so porting was the only way to reach them. Soon there might be a small but (hopefully) growing market of people who like to spend money on quality computers and software but can run Windows and just need to be convinced to install Windows.
Apple could still have the market of people who like PCs that are stylish and just work and come with Mac OS X pre-installed, but still offer Mac OS X to people with PCs. I'd be happy to accept a much stricter licensing/activation situation in return for this, a la Windows XP.
Selling software has made Microsoft billions. Microsoft had the software people needed in the 80s and 90s... Office software. Apple has the software people need for the present and future... iLife with iTunes, Spotlight, Mail/iCal/iChat/AB, Safari, etc. Unless moving to Intel makes Apple's PCs truly price-competitive with other vendors' products (ie: get Apple value-added without the cost-added) their installed base will still be dwarfed by Windows.
All that said, I really want one of those Mac/Intel boxes. Now. :-) And it has the software I want... NOW!