I'd never say never
We always have a lot of ideas floating about for new things we could try. Although I have to say that a DVD authoring program isn't something we've considered up till now.
Like Axeman says, our main focus at the moment is the current programs. We still have a huge list of things we want to do with them. Currently we are a relatively small team, so we don't really have the man power to create the shear number of products Adobe does. It's better for us to focus on making a few really good products.
Having said that, we are growing rapidly as a company, and soon we will have a lot more resources to play with. Our business model has always been to listen to what people want and then try to create it for them. So we're very interested to hear the areas people think we should expand into.