About as silly as all those people holding ipads to take pictures too lol. That has to be the dumbest thing I have seen yet. People holding 10 inch camera so why not phones? But no if there is an ipad mini I would say no to a native phone app.
I disagree.
Taking photos with your ipad so the pictures are stored inside to be instantly inserted into a document or uploaded to some blog or photo-sharing site, or ready to be edited via iphoto/imovie without having to fiddle with photostream, email or sd cards? Well worth any perceived inconvenience of holding a larger tablet over a smaller phone.
Having done so extensively in and out of my classroom (e.g.: I want to take a snapshot of a pupil's work to show via skitch or educreations app), I can confidently tell you that the ability to take high-quality pictures with your ipad is a vastly underrated ability which is not receiving its proper due.
Anyways, regarding the original question, you would probably be able to simulate calls via facetime and imessage, just like with the current ipad. But unlikely it will have any true calling capabilities.