I don't actually own an iPad yet, but I've been playing with the iPhone/iPad simulator which is part of the iPhone SDK (Software Development Kit). Using this as my model, I've been able to add iPad detection to the WunderCounter, so that your account will properly detect this device once it starts to ship out to customers. If you're curious, the actual iPad UserAgent string (according to the simulator) looks like this:
Mozilla/5.0 (iPad; U; CPU OS 3_2 like Mac OS X; en-us) AppleWebKit/531.21.10 (KHTML, like Gecko) Version/4.0.4 Mobile/7B348b Safari/531.21.10
On a related note, the Perl module HTTP::BrowserDetect now also has support for the iPad. It will be available on the CPAN in the next day or so.