My latest Mac (well, Apple) related purchase was the keyboard+dock stand for the iPad. I really wanted to see if one could use the iPad as a basic word processor, which you really need a keyboard and stand to accomplish.
The answer: Yes! I don't think I'll keep this, however -- I may just get a "regular" Apple BT Keyboard instead. The stand is very nice and all, and I like the iPad-specific function keys, but it doesn't work with a case on the iPad and I can see how removing the case each time you'd want to use this would be kind of a pain over time (even though our case actually makes it pretty easy to remove/replace the iPad).
I used iAWriter as the WP program, though of course there are many others. It's focused on making you
write, less on formatting, which is a good thing. I find the focus factor is excellent, and this particular program can be set up to sync with Dropbox, so you can easily move texts over to a "real" computer for formatting or serious/complicated editing.
The Apple iPad dock/keyboard does have a nice feel, holds the iPad at an excellent angle, and requires no batteries (unlike a Bluetooth one of course). It can also be used to charge the iPad or run audio out to a stereo.
But for basically the same money you can just buy an Apple BT keyboard which will work with both the iPad and other devices. If your iPad case allows you to prop the iPad up vertically or in "typing mode" then that plus a BT keyboard pretty much duplicates the functionality without tying you to strictly to a desk (though a desk is still the best place for any serious amounts of typing). You won't get quite the same really nice angle from most cases, but good enough.
Another advantage of the regular BT kb instead of this is that the fixed dock makes this device more unwieldy to carry around. I've seen some nice cases for the BT keyboard, but even without one it fits in a backpack or briefcase quite easily -- whereas the keyboard+dock really doesn't. I think someone would look perhaps pretentious pulling out the kb+dock and iPad at their local coffee shop, whereas putting the iPad at its usual "typing angle" in a case plus a BT keyboard would look less obviously "I AM A WRITER WHO IS DOING SOME WRITING NOW."
Before I return it, however, one more test -- I'm going to put this in front of my wife, who currently uses a Mac mini to type online in various forums and Facebook and Livejournal. Let's see if this gadget can get her to ignore the mini and use the iPad for that sort of stuff instead.