Within a week of its release, iPad is hacked by the famous iPhone hacker George Hotz. He had a posted picture of hacked iPad running blackra1n (jailbreaking tool) and Cydia. This means that a new version of blackra1n may be released soon. It is also interesting to note that the exploit screenshot was released just within one day of posting the iPad firmware 3.2 encryption keys.
The advantages of Jailbreaking iPad
Jailbreaking iPad opens up more possibilities than on an iPhone. iPad has better hardware and bigger screen and hence it can replace a netbook with much better battery backup. We may see custom Linux distributions capable of running on iPad. The immediate benefit of course is that iPad users can download applications rejected by Apple from other app directories such as Cydia. It also enables complete customization of iPad OS. Who knows, someday someone may even find a way to run Windows XP on iPad!
However the lack of some of the essential hardware on iPad makes jailbreaking less appealing. For example, lack of an integrated camera.
How blackra1n works on iPhone?
Blackra1n works on a specific exploit on iPhone/iPad devices known as the USB Control Message exploit. By manipulating the call to function usb_control_msg it is possible to overwrite sections of memory. See this page for the details of this. However in the case of iPad, the precise exploit that Geohot used is not yet known.