http://www.mobilenapps.com/articles...significant-design-changes-souped-up-spec.htm
If you do a google search is mentioned in numerous places also.
The point was for the person in question, as he was unable to name a source before.
These rumours and all the links they link to originally seem extremely vague at this stage. If somebody would have true knowledge they would post some specs, not ideas of where the specs could be headed. I could be wrong, but so far I think the rumor scene is simply producing hot air in terms of iPad Pro rumors.