Since it seems on-topic, I might as well post the results of some (incredibly small scale) tests I just did. I have been unable to acquire either
[Illustration of the Dragon Soul] or
[Eye of the Broodmother], so I performed a few short tests with the four trinkets I do have:
[Sundial of the Exiled],
[Dying Curse],
[Elemental Focus Stone], and
[Living Flame]. For these tests, I ignored the hit rating of the trinkets, using buff food or equipping Living Flame and not using its on-use to make sure I was hit capped. Tests ran approximately 2 minutes and 20 seconds each on a heroic training dummy and I ran two tests for each trinket. For Living Flame, I used the trinket immediately before the second Lava Burst.
The results very clearly show the focus stone as underperforming. I expected it to be a lot better than it was, but it was several hundred DPS behind Living Flame. Living Flame was the second worst trinket, but it was extremely close to Dying Curse - easily within the margin of error for such short tests. I think Living Flame vs. Dying Curse depends on how much hit you need and whether you'll remember to use Living Flame. When assuming you have all the hit you need (thank you, T8), Sundial actually came out on top by about 200 DPS. The Sundial test was the only one where I broke a 4k dps average (although I did get that high using Dying Curse on a single test, the following test was much lower, dragging down the average). If anybody who has done more extensive testing (it wouldn't be hard, these were very minimal) has data to correct me I would love to hear it. I just did the tests for my own purposes to determine which trinkets to use on my guild's Yogg attempts tonight, so I was in a bit of a hurry.
Related to the gemming discussion, it seems like a no-brainer that given
[Conqueror's Worldbreaker Hauberk] and
[Eruption-Scarred Boots] for a Jewelcrafter, you would place a Runed Dragon's Eye in the boots and ignore the socket bonus on the chest. Why, then, does Rawr recommend that I put a Runed Dragon's Eye and a Reckless Monarch Topaz into the chest, and a Runed Scarlet Ruby into the boots? Losing 8 spellpower for 8 haste seems like an obviously bad trade. Could it be that at my level of haste (493), the extra bump over 500 haste would do something special for me, or is Rawr just acting up?