Jamplay completed the conversion in a fairly short period of time, and has provided weekly updates in their forum as to which videos have been added to the iPad/iPhone compatible list. They ran a script on their server that converted all the videos to HTML5.
Guitartricks hasn't even committed to doing any kind of conversion. I agree that they have no obligation to cater to apple product owners, but it's not like apple invented HTML5. It's a better, less memory and processor intensive product that many websites are moving toward.
Kevin