Very interesting read, not in the least because it's written from the point of view of a RISC OS user. Besides, I love reading Martin's articles!
While iWork is a very capable suite of Office apps, its file compatibility with MS Office is not 100% for obvious reasons. I guess it's comparable with OpenOffice in that department. Of course, MS Office for Mac is fully compatible with its Windows counterpart, including workflow.
Apple moved to widescreen displays early on, for various reasons. To tell the truth, I'm not even considering moving back to the old square non-widescreen modes! Regarding the MacBook - it indeed tops out at 1280x800 pixels, but the 15" MacBook Pro as mentioned in the article has a native resolution of 1440x900, I believe. A 17" MBP is on the cards with a higher resolution. All Macs also have a DVI output to drive an external screen. However, Mac OS X allows icons and the Dock to be scaled at the users' preference, which may help. I guess a system (Unix terminal) hack is possible to allow windows to cover the Dock, but there's also a GUI option to hide the Dock until the pointer approaches it. That way a user can use all the screen space, except for the menu bar at the top.
Every user with an account can choose their own systemwide language, including British English. Every installed app will then use it, if available. To change the spelling, look in one of the menu options in the menu bar or right-click inside a text field. Look for the 'Spelling...' entry. Indeed, one can right-click on a Mac since the dawn of Mac OS X in 2001, but Apple standardised it since 2005. Even the new MacBook (Pro) glass trackpads will detect a right click, or up to four fingers simultaneously. The trackpad is the button, so perhaps it takes a little getting used to. Cut & Paste is possible via keyboard shortcuts, but also by right (or Control) clicking inside a text field which opens a contextual menu. In Safari, one can simply drag off any website image and drop it in in a Finder window or into another application, just like RISC OS. In fact, many Mac OS X operations can behave quite similarly to RISC OS operations, including moving windows (or scroll bars) without raising them to the front of the window stack. Just hold the Command key to do this.
Overall, it's quite educational to explore the system with the built-in Help app, which can always be accessed via the Help menu entry at the far right of the menu bar. By the way, Leopard wasn't released at the start of this year, but in fall 2007. In my opinion, an Apple Macintosh is probably the most suitable system for any RISC OS user in need of a modern supplement, because of its overall similarity to an Acorn computer - regarding both hardware and software (OS).