This isn't a technical challenge. The iPhone and iPad industries didn't exist. Everything beyond the cell companies was wide open. Anyone writing an app for anything that didn't offend Apple or it's customers, was free and clear.
But what kind of apps do folks want on their appleTV? Content apps. Content providers go back dozens of years, with hundreds of companies and thousands of existing relationships. Even then, there are still content blackouts and other hot conflicts, as companies fight for money and control.
I ignored the appleTV until this year, when I could suddenly watch HBO. What does HBO's parent company do when one of the new apps starts sharing some of its other content outside of years of negotiations? Why pull the plug on the dedicated app, of course. This is the same industry that delayed HD content for a decade in fights over display and transmission standards, they are not going down so easily.
We won't get such easy options until enough of us have already abandoned the existing channels, that they don't have a choice. Until then, Apple must work one relationship at a time, piecing together a new lineup to feed a new device.