No, the new 5.6 V8 is intended for the Ram 1500. The Ram 2500 and 3500 will still have the big in-line 6.
From what I've been able to piece together, I'm thinking that the 4.2 V6 will go in the Durango, the Dakota, the Grand Cherokee, and the Wrangler. The 2.8 I4 will go in the Liberty and...