Difficult question. I would say: go for consistency, so go for as much Mountains possible, but probably don't drop Wasteland. Reasoning: a little protection against lands.dec and other pesky utility-lands. Also, with TC floating around the whole mana-denialplan will probably fail anyway. As for a splash: I am looking into White myself.
Rest in Peace is probably one of the best post-TC meta hosers available right now.
Thalia, Guardian of Thraben, while better with manadenial, will still be decent enough. I'm not sure if Goblins will survive in this meta. WotC is making it increasingly difficult to not play Blue. As for me, I don't play Blue. Periodly. I don't want sound like a Grumpy Old Man, but I will also be looking into other ways of making Goblins viable.