We'll see. Statistically speaking though, all you have is hope. Again, I'd love to see it succeed because that means we'll still get X-Men movies and hopefully in a broader sense given how many options they have with X-Factor, X-Force, and solo spinoffs with Wolverine, Deadpool, etc. But historically, the license just hasn't had the "oomph." Even when you look at FC, it was the second lowest performing of the whole franchise, so it really doesn't bring much to the table. It's Jackman and the rest of the older cast from the originals, FOX is banking on.
As for Cap, again, it's a direct tie-in to Avengers 2. Redford's no schlep in Hollywood, then you have Jackson and Johassen returning, plus the intro of Falcon. There's all kinds of reasons as to why it very well could easily do better than IM3 and Thor.