I am a long time linux user, and just got an iPad as a gift. The first shock came when I turned it on, and found that it won't do *anything* until you hook it up to a computer with iTunes on it. There is no iTunes for Linux, iTunes doesn't work under wine (Linux's Windows emulator), and I have no intention of installing Windows in a VM on my Linux box. I believe that the WIndows EULA specifically prohibits installation on a VM anyway, for those who care about following the terms of the EULA. Fortunately, there was an Apple store nearby, so I was able to take it there to be actviated.
I have to admit that the iPad is a sweet little device, but I am really used to telling my computer what I want it to do. The iPad is more of a device that tells you what it will let you do. As with most things Linux, there are ongoing projects to make the iPad workable under Linux, and I will be trying them out as they develop.