I learned this the hard way, having bought a Microsoft Comfort Curve 2000 ergonomic keyboard. That's a wicked keyboard, by the way, if your shoulder width is not so wide, because it has only a slight curve, rather than the dramatic curve of other ergonomic keyboards. It also has a light but distinctive touch, so it's easy to press the key down, but not so easy that you would accidentally "smoosh" a key down by accident. The key's travel is also quite short, so it's less finger motion required to type.
Unfortunately, installing the IntelliType software seems to have caused kernel panics for my MacBook Pro on the order of once or twice a day (under heavy typing load. That meant I lost a lot of programming and typing of emails and reports. sigh
The solution is simple: uninstall IntelliType. The uninstaller is in the Utilities folder in the Applications folder. But that's not a very good solution by itself, because the Command/"Apple" and Option keys are reversed on Microsoft keyboards compared to Mac keyboards. So here's the other half of the solution:
For some reason, Apple's own Keyboard preference pane doesn't work for remapping the common keys. It's supposed to work, but it doesn't for me. No idea why.
What works is this:
You need KeyRemap4MacBook and maybe the PCKeyboardHack. They are free and open source software, it seems. Not the most user friendly, but quite easy to understand.
With KeyRemap4MacBook, you'll need to check off the following options (at least for my MacBook Pro laptop):
- Don't remap an internal keyboard
- Don't remap Apple's keyboards
- Command_L to Option_L
- Command_R to Option_R
- Option_L to Command_L
- Option_R to Command_R
I use the capslock key as an extra control key. For this option, you'll need PCKeyboardHack. In it, you'll need to check off the "Change Caps Lock" option, then double click on the keycode and change it to 59.
The keyboards multimedia keys will still work, but the quick launch application keys won't. Oh well.
The fix I suggest above does have one implication though for the IntelliPoint settings: if you set your mouse button to press a key chord sequence, you'll have to set it pretending that the keys pressed are the ones on an external keyboard. So if you want the key sequence to be effectively Command+O, you'll have to set it to Option+O (using the suggested configuration above).
 All evidence means my personal experience with using the Mac with the Microsoft IntelliType software installed, and the Microsoft keyboard plugged in for 1.5 months, and comparing that with using the Mac without the Microsoft keyboard plugged in for another 2.5 months. Plus the reports of others from across the internets.