Anybody predicting 300+ carries this year, not to mention without some semblence of an injury, is STRICTLY optimistic at best.
Let's consider the facts. When was the last time Ronnie Brown carried such a load against talent like he's facing in the NFL? Nobody can definitively say that the only reason he didn't get the full load was because of Caddy being his teammate at Auburn.
His physique is built for it, at least I think so. But this is only season 2. Ronnie's going to need to be spelled quite a bit so we don't burn the guy out. You don't just jump from a 2 back committee at Auburn and a 2 back committee in his rookie season with the Dolphins to be THE GUY. There's an adjustment period. Year 2 for Ronnie is that period.
IMO, you cannot deny that he ran 20 times better with Ricky sharing the load last season.. Now, you also have to factor in the rookie learning curve in the year, but fact is teams were being bulldozed by the two of those beasts. Ronnie got to take advantage of being fresher and capitalizing on worn out defenses because of the two of them.