I expect a lot more out of Howard on the Rockets, I think mentally he never bought in to the Lakers team last year and as a result of the injury as well as not caring he didn't play as well as he did in Orlando. I've heard a lot about his injuries possibly signaling the end of his effectiveness, but I just don't see it, he is still one of the top centers in the league. The rockets are a major step up from the Lakers, as well as any team that Dwight ever played with in Orlando. Their offense will be much more effective, the combination of James Harden, Chandler Parsons, and Dwight will be very effective. Dwight's arrival will really make Chandler Parsons better, I can't imagine how many open shots he will get.
Defense will also be greatly improved with Dwight, last year Dwight didn't play as well on Defense but he was also playing with a group of players that had a cumulative athleticism of a sloth. The athleticism in the Houston will allow for better wing defense as well as stopping other teams from just out running them in transition which is what happened last year.
Overall I think the Rockets are going to be a contender for sure, and I like their chances. They are definitely on the short list of teams that could win a championship next year.