It all depends on what the EPA regs are going to look like in the future. If the CAFE regs are too stringent, the 6.2L engine itself might become a rarity and smaller more fuel efficient engines (i.e. the 5.0 Coyote) will replace more of them. It does not mean the 6.2L will totally go away, they just will be installed in fewer vehicles to meet overall company-wide CAFE.
Now, there is a possibility for the 6.2L modular to become much more fuel efficient AND actually much more powerful too: going DOHC with TiVCT, EcoBoost (especially the Direct Injection part), and if Ford ever adopts it, cylinder deactivation to supplement all this other stuff. The key problem is the cost in paying engineers to redesign the 6.2L to use all this crap, designing all this crap to mount onto the 6.2L, and even more expensive, retooling the engine plant lines to start building this engine this way.
Squirrel of Death!
Do not **** off the SoD!!!!