Is there a published product roadmap upcoming products beyond Enter the Unknown?

Not yet, unless you also want to throw in Age of Rebellion (Core Rulebook in 2014) and Force and Destiny (Core Rulebook in 2015).

I believe they stated a while back that they don't plan on making public a roadmap of the EotE supplements in case something happens and they aren't able to hit a projected date. That being said, it looks like they plan to give substantial support to the line considering within a couple weeks of the core rule book release we already knew that they first adventure book and career supplement would be out in a few months. Personally I'm cautiously optimistic at the rate of releases.

We'll probably have a better idea of what FFG's schedule for their Star Wars RPG line entails after this year's GenCon.

I am actually glad they are playing it close to the vest. I get tired of constant griping about missed deadlines, and I get just as excited and then disappointed.