Huh? What does this have to do with Gates? Under Gates leadership MS has been developing software for Apple since the 90's.
Edit: Fixed possible factual error.
Edit: Fixed possible factual error.
Gates has attacked the iPad on every interview claiming that it's useless.
I think that's a little unfair. The technology just wasn't ready yet. The one place they got it really wrong was with the OS but we didn't have WiFi yet (well most people didn't), we didn't have the kind of touch displays we have now, flash storage wasn't cost effective so they probably used HDD's. They had the general idea right but were too early. Unfortunately when the tech was ready MS was too slow.
http://en.wikipedia.org/wiki/Windows_for_Pen_Computing
(Watch some of the youtube demos, really cool)