The change may not come until next year, or in three years, but it will inevitably come. And when it does, you'll be much better off if your derivatives valuation models can be easily ported over from your old system to your new system. This results in faster and cheaper implementation of the new system, since you won't have to spend money rewriting large part of your derivatives models. And the models which use to work on your old system won't become broken on the new system. In other words, your derivatives software should be platform independent.
Platform independence means two things in the context of derivatives software.
First, the option pricing models must be available as subroutines, callable from any programming language. Second, the subroutines must run on a variety of different machines and operating systems. If there is a user interface, make sure it is easy and safe to use. This means that you can enter deals quickly, without a lot of pull down menus to go through. More importantly, the best user interface cuts down on input errors, which will cut down on misquoted deals.