Well the iPad is HD, From wikipedia.
http://en.wikipedia.org/wiki/720p
Being 1024×768, it qualifies as HD since the vertical resolution is greater than 720.
1280×720 is for a 16:9 aspect, for 4:3 its 960×720, which the ipad is greater than so its HD, just in a 4:3 Aspect ratio.
I'm gonna make millions with these 1x1080 screens I'm selling then.