I may simply be missing something but I think HTML and Javascript make a lot of sense for basic applications. I've never quite understood why someone would want to jump into Silverlight for an application that simply handles data input and retrieval. I also know that Silverlight has capabilities that HTML doesn't but it's also got some deficiencies that IMO are glaring.

There is a lot to be said for what you are comfortable with using but at the end of the day HTML is a truly cross compatible technology that is becoming more and more capable every day. This could also bring in a lot of potential "developers" if the cost of entry is lowered.

I also understand that you don't want the technologies that you invested in to become extinct overnight but I simply can't imagine that happening.