Let's try something: Grab your iPad, boot up Pages, Keynote, or Numbers, and try to print something from each app.
Can't do it, can you? Checking the support page for each, though, brings up this intriguing message: "printing directly from [the] iPad is not currently available." NOT "you can't print at all," but "you can't print now." The best you can do is to send the documents to a desktop computer that CAN print 'em, either via email or the iPad's new File Sharing feature in iTunes.
All that could change this Thursday when Apple unleashes OS 4.0. AppleInsider suggests that the ability to print via Bluetooth or Wi-Fi could be one of the OS's new features — bypassing the galaxy of buggy print drivers that plague both PC's and Mac's.
The question is: will that be a "likely" feature, or an "it would be nice if…"?