Do you know how it works on the iPhone, they haven't changed anything ?
It looks at the type of web browser that's viewing the page, the iPhone sends a string ( user agent ) including the text iPhone, the iPad will send the string iPad.
Mozilla/5.0 (iPhone; U; CPU like Mac OS X; en) AppleWebKit/420+ (KHTML, like Gecko) Version/3.0 Mobile/1A543a Safari/419.3
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/7B334b Safari/531.21.10
If they don't see the correct string it will send flash, the iPad isn't even out yet in the UK, why would they even bother changing anything till is out.
http://whatsmyuseragent.com/