Software compatibility will sort itself out, mainly that the developers will put new programs ready for retina. Its been out for less than a month, give a little time.
Regarding running windows on a mac, I still find that its good enough for my needs, I mainly run windows on it, since I depend on stock trader platforms, and those are windows only here in Brazil. I do prefer to run OSX, Im OS agnostic though.
Regarding running windows on the RMBP, you are going to face the issues of setting the res to 2880*1800, better is to use it in a VM, its easy and simple to do. Or just put the res at a lower level, like 1440*900, its possible and easy to do, a simple right click solves this.
The main problem with the res in windows is that the scaling there is the problem, you can adjust the dpi settings (its also very simple to do, a right click and some left clicks). Some apps look blurry or dont scale well when you put the dpi to higher than 100%, some not all.
Since you are business student, you are probably going to use statistical software and some business managment tools and those are VERY light to run, specially on the level that you are going to use, you wont run high end statistical analysis now, when for a MBA possibly.
I would still advise against a mac on uni environment. I dont know if its me, but Im rather clumsy, spill beer, trip over things and so forth. For my first 3 years of college I used a thinkpad, next business day warranty, with accidental damage protection, thus downtime without a pc when I sorely needed one rarely happened. And this is something that apple cant match here in Brazil, dunno about where you are.
I do like the RMBP a lot more, it fits the weight that I would carry (I go out of my house at 6am and return at 11pm), however for people that need the machine working non stop its a difficult choice.
The thinkpad W530 should fit your needs rather well. The gpu is less powerful, it weights a little more, but the warranty is better.
Be warned that you are still going to do away with some space in your SSD running a VM, windows 7 uses around 20gb coupled with the software that you might need, mathematic, eviews.. it should take out around 30-40gb.
And once you go SSD, you never go back.
I know no matter what I choose I will still love the decision I make because both are actually great machines to begin with!
