You are creating an application today. It will not be Unicode compliant. Why? For older programs, it may not be worth the rewrite effort, but if you are writing code from scratch, intended for a worldwide audience, this would seem to be automatic, and yet it doesn't seem to be. What are some of the challenges you face in creating software that leaves the ASCII character set of yesteryear behind (except for backward compatibility)? Be as technical as you want, don't worry about it being over my head. Maybe it will be, but I can still use it as a starting point for further research, and others will benefit.
On the other hand, be as non-technical as you want as well. I think I am seeing a trend of requesting Unicode support for various DonationCoder applications (maybe I am just noticing it more now that I am learning Devanagari script), so I think a lot of people want to know why this isn't easy!