Depends what that student does. I've just ditched my 2013 15" rMBP, mainly because of the weight (i carry a lot of camera gear too), but partly because it was getting to the end of it's Apple Care and I'd depreciated it in my accounts anyway - time for a new one. I wanted a lighter 15" with much, much more RAM for the VM's I have to produce for my other day job, but that didn't arrive at the WWDC. So to cut a long story short I got a 13" rMBP. it's £100 more expensive than the Mac Book for the i5 model (2.9Ghz, 8GB, 512GB SSD), but it's much faster, has a better keyboard and a better trackpad. Okay so it's 1/2KG heavier, but I can live with that. The Air didn't come into it because the screen just doesn't cut it.
So far I'm really impressed. It's light and for every day stuff it's great. I've just done an import with Photo Mechanic and it's all good. Just running a Lightroom import of 150+ photos and building 1:1 previews and the performance is fine - the machine is still responsive while I'm doing this. I was concerned that 8GB RAM might not be enough, but that's fine too.
So to go back to your question the 13" rMBP is a very nice machine. Okay it's not Skylake, but you probably won't notice the difference and unless you specifically need USB 3.1 or Thunderbolt 3. it's a great little machine and there's no reason to wait for Skylake, etc if you don't already have a laptop. I bought it with the intention of it being the my temporary laptop until Apple release another high-end one, and then it replacing the ageing 11" MB Air that is the family laptop. So far I want to keep it though. See if my work requires me to have anything faster as I don't want the extra weight or bulk of the 15" rMBP.