Obviously the off season is not anywhere near done, but I thought it would be an interesting review of what the Dolphins have gained and lost so far. Breaking these changes into three situations, here is what you get to this point:
Ellerbe for Dansby
Wheeler for Burnet
Keller for Fasano
I think this shows the Dolphins still have a lot of work to do. The trade-offs I think are straight forward changes in personnel due to scheme - a pass catching TE over a versatile TE and two LB's better at blitzing than pass coverage who are also younger and faster. These three moves seem to be a positive in that they fit better with the offensive and defensive schemes that are being implemented.
The WR additions without losing anyone is a huge improvement - potentially taking the group from a bottom 5 group to a top 10 group in the NFL. Adding Keller as a pass catching TE and a better year from Charles Clay really makes the passing game the area on the team with the greatest chance of improvement.
It is the subtractions so far this off season that there remains many different opinions. Were the Dolphins too quick to move on from these players, all of which are still in their late 20's and still in the prime of their careers. If they continue to be productive there will be a lot of hand wringing by Dolphins fans on cutting these guys loose. But if Long remains injury prone, Smith's immaturity keeps him from progressing, and Bush loses a gear that makes him less dangerous and only a part-time player, then Ireland and Philbin will look like geniuses for not overpaying on any of them.
Most importantly now is what the Dolphins will do to replace these three departing starters with hopefully at least an equitable value. If Eric Winston is brought in at LT (seems like a likely possibility with him visiting today and mutual interest) this would give the Dolphins two tackles that match the zone blocking scheme preferred by the team currently. Winston and Long are the same age so a potential 3-4 year contract here is possible.
Replacing Bush and Smith is a little more difficult and not as clear where the team is heading. There are no equal values in free agency, although there are some older or previously injured veteran CB's that could come in and have a positive impact. At RB there are really only workman-like type RB's left and no one as dynamic as Bush. So at this point it looks like the best way to replace these two positions are in the draft, CB with an early round pick (or two) and maybe a RB in the mid rounds (4th or 5th possibly).
If they can accomplish these things and add a few more pieces in the draft that actually get on the field (S, OG, DE, TE possibly?), most would look at the overall changes in personnel as at least on paper an improvement from last year's team. Pretty exciting.