I've been in a pre-launch guild for SWTOR for over two years, so it certainly better not dissapoint.
Seriously, I think it is going to be the next truly large main-stream mmo. I'm not saying that it's going to reach 'wow' size, only time can tell that, but I think that it will likely prove to at least be the largest since WoW. Being in the star wars franchise, it has the long-term fan-pull. Also, star wars also has a strong pull on the general population.
Aside from that, they have the resources and time to create a truly extensive game. We'll just have to wait and see.
And cortosis is not only resistant to lightsabers, but can also short out lightsabers on contact.