I don't even pretend to know jack about such things, but I remember reading that this new JailbreakMe.com jailbreak is what's called a "userland" exploit, meaning that, unlike most previous jailbreaks where you had to get PwnageTool and do all sorts of voodoo magic to an iOS software update package, it doesn't get in through the bootloader, but rather a security hole in an already-running OS. Maybe that limits the scope of what can be done to the iPad? (i.e. we can't get at the bootloader because the iPad 2's bootloader still hasn't been cracked open yet, or something to that effect we can only use tweaks which take effect after boot)