Hardware wise, current MBA is understandably lack lusting over the new iPad. Retina display, a GPU that even more powerfull than Intel HD 3000 on MBA, enough CPU for daily computing needs.
All it needs is a serious OS like OSX. It has full blown Photoshop, Illustrator and whatnot, a proper office apps for writing essays, art students still have to write essays, right?

And since OP is in university, even if it's art major, a proper laptop is a necessity. I'd make it a primary choice, and if within a year or so I have spare money, than I'll get an iPad, who knows wha Apple would have on the next iPad.
So yeah, unless you have an adequate laptop/desktop, go with MBA first. iPad is a secondary device no matter what, maybe not because of the hardware anymore, but more to the OS. If iPad runs full OSX, wow .. I don't think MBA would be able to hold a candle against it, just snap the bluetooth keyboard and trackpad, and voila .. a proper laptop with reasonable power .. but fortunately we're not there yet.