I am the development coordinator for one of the world's leading wagering software development companies.
Having a background in industrial automation and other real time software systems, I can tell you that writing software for gaming (especially when it involves racing) is easily of the same order of writing sharemarket trading software. As its essentially what it is - a great big real time bank. Most of the things you would like to do as batch can't be done, as it can be with a bank, as balances and histories need to be available straight away.
Most of the guys that work for me have masters degrees (I have the full set) and all need a broad experience in a variety of areas to be even able to work here. Every thing you do touches on performance, scalability and reliability.
If you worry about the morality of it you're probably wound too tight to be working anywhere. And how many of these hiring companies, especially in america, see military service as a moral plus? If the job interests you do it. If it doesn't don't. And if you're any good and want to work in Australia - send me your resume :-)
Cheers, Brad
PS. The one thing I have found doing this, having a PhD, is I understand how the guys working on things like the Manhattan project must have felt. Not commenting on the morality or anything of it, but just how little you think of what it is you are actually doing. For example, rarely do you think of it as being horse racing - all you're concentrating on is getting the right prices in the right columns etc. You just don't think too much about the bigger picture. Just something I found interesting.