I just managed a project for my team that involved integrating a number of different proprietary software tools, and the experience has made me want to star far away from IS.
Picture constant fighting over scarce development dollars, requirements that change, change, and change again, stuff that never gets nailed down, business constituents that don't have a copmlete picture of the impact and role of their work, and finally, after all the headaches and spreadsheets and hour long meetings, when the testing finally is satisfactory, senior management implements a production feeze and you have to wait 6 months to roll it out.
Honestly though, if you really love IS, this kind of thing won't bother you too much.
As odd as it might sound, if you like programming, you might consider accounting. I was a portfolio accountant for a couple of years and spent lots of time building custom spreadsheets and creating VBASIC macros. To me it was really challenging and fun.