While Celestalon and the WoW dev team may be happy with the eclipse mechanic, in my view the whole mechanic does not provide much thoughtful gameplay. Currently, moonkin dps is like a nice regular sine wave, it oscillates up and down at very regular intervals with higher peaks corresponding to specific fight amp mechanics and/or cooldowns. While this "works" from a mechanical standpoint, it does not provide much room to make the types of interesting decisions (such as damage now vs. damage later) that make WoW such a great and fun game.
The problem as I see it is that the eclipse mechanic has no leeway (I could say "very little leeway" but the point is the same) in being able to make the decision of whether to trade off single-target damage now for increased single-target damage at a later time (in the near future).
There are countless ways to approach this problem mechanically but I have focused two of my suggestions on already existing mechanics that could likely be easily implemented with limited changes to the current eclipse mechanism as well as keeping the "feel" of moonkin gameplay almost identical to where it is today.
Solution 1: Change Euphoria
(New) Euphoria
Requires Druid (Balance)
Requires level 38
While not in an Eclipse state, your Wrath, Starfire, and Starsurge spells generate double the normal amount of Solar or Lunar energy. In addition, casting a non-energy generating spell while not in an Eclipse state generates [100%] of the normal amount of Solar or Lunar Energy in addition to storing [50%] of the normal amount of Solar or Lunar Energy (whichever is more beneficial) for use in the next Eclipse state.
Explanation: What this will do is to allow balance druids to "store" eclipse energy by lengthening the amount of time they spend outside of Eclipse. For example, let's say that you have a moderate burst phase incoming in the near future and you are leaving Lunar Eclipse on your way to Solar. Instead of casting Starfire which would have allowed you to get to Solar eclipse in 3 casts, you could cast Wrath which would still move you towards Solar but at a reduced rate - you would need a total of 7 Wrath casts to get to Solar that way. In exchange you will have "stored" ~55 more Solar Energy that will allow you to cast 3 more eclipsed Wraths.
The tradeoff here is adding 6 seconds of uneclipsed time to the eclipse cycle and getting 3 more eclipsed Wraths vs. the "standard" rotation.
Solution 2: Change Euphoria
(New) Euphoria
Requires Druid (Balance)
Requires level 38
While not in an Eclipse state, your Wrath, Starfire, and Starsurge spells generate double the normal amount of Solar or Lunar energy. In addition, casting a non-energy generating spell while not in an Eclipse state generates [100%] of the normal amount of Solar or Lunar Energy in addition to extending the next Nature's Grace buff by [1 second].
Explanation: In this example you will have "extended" the next Nature's Grace by 7 seconds by stretching the time you spent out of eclipse by 6 seconds.
Obviously the numbers need to be tweaked quite a bit to get to the desired result but the idea is that overall it should still be more dps on a patchwerk style single-target fight to do the rotation as it currently exists. The important thing is to offer the option to make a thoughtful tradeoff about whether it is better to do less damage now vs. more damage in the future. One of the other benefits to this type of tweak is that it allows moonkin to "stretch" out the rotation to better fit the timing of a wider variety of fight mechanics. As it currently stands, moonkin need to hope that high dps phases miraculously align themselves with their eclipse cycles.
-Pippilongear