I started writing a DPS simulator a couple months ago but haven't had as much time as I'd like to keep working on it so one of my guildmates suggested I post it here. I'm not sure how to describe it other than to say it mimics the game rolls and rules which should be the most accurate way of determining how DPS is affected by different elements.
Currently, the program allows the user to input spell damage, crit rate, and hit rate. Then it outputs a log of the spell results and calcuates DPS and other statistics of the simulation. Here's a sample of the program output:
Caster Stats
=========================================
Spell Damage: 1150
Crit Rate: .36
Hit Rate: .16
Combat Log
=========================================
[ 3.0] Fireball hit 3103
[ 6.0] Fireball hit 3007
[ 9.0] Fireball hit 3108
[ 12.0] Fireball hit 2993
[ 15.0] Fireball crit 6701
[ 18.0] Fireball crit 6183
[ 21.0] Fireball crit 6656
[ 24.0] Fireball hit 2988
[ 27.0] Fireball hit 2961
[ 30.0] Fireball hit 2986
[ 33.0] Fireball crit 7322
[ 36.0] Fireball hit 3573
=========================================
Damage: 51581 Time: 36s
Ideal DPS: 1432.81
Fireball - 12 casts
-----------------------------------------
Hits: 8 66.7% Max: 3573
Crits: 4 33.3% Max: 7322
Resists: 0 0.0%
You'll notice that for the last 2 spells, the damage is a bit higher thanks to Molten Fury. This is much better than just estimating that Molten Fury is worth 4% overall damage since it is difficult to determine how other dynamics (procs, trinkets, boss dying faster) come into play.
I also have a system in place for managing buffs and proc effects. This simulation was run with the same parameters as the above, except that I increased the targets health and enabled the Mystical Skyfire Diamond (v2.3) proc and Shiffar's Nexus Horn proc.

Caster Stats
=========================================
Spell Damage: 1150
Crit Rate: .36
Hit Rate: .16
Combat Log
=========================================
[ 3.0] Fireball hit 3168
[ 6.0] Fireball hit 3172
[ 9.0] Fireball hit 2999
[ 12.0] You gain Call of the Nexus.
[ 12.0] Fireball crit 6196
[ 15.0] Fireball crit 7433
[ 18.0] Fireball hit 3555
[ 21.0] Fireball crit 7010
[ 22.0] Call of the Nexus fades from you
[ 24.0] Fireball crit 6176
[ 27.0] Fireball hit 2977
[ 30.0] You gain Focus.
[ 30.0] Fireball crit 6586
[ 31.5] Focus fades from you.
[ 31.5] Fireball crit 6250
[ 34.5] Fireball crit 6583
[ 37.5] Fireball hit 2970
[ 40.5] Fireball hit 3165
[ 43.5] Fireball hit 3025
[ 46.5] Fireball crit 6354
[ 49.5] Fireball crit 6299
[ 52.5] Fireball hit 2956
[ 55.5] Fireball hit 3064
[ 58.5] Fireball crit 6413
[ 61.5] Fireball hit 2980
[ 64.5] Fireball hit 3075
[ 67.5] Fireball hit 3016
[ 70.5] Fireball hit 2989
[ 73.5] Fireball hit 3172
[ 76.5] You gain Focus.
[ 76.5] Fireball crit 6433
[ 78.0] Focus fades from you.
[ 78.0] Fireball hit 3179
[ 81.0] Fireball hit 2953
[ 84.0] You gain Call of the Nexus.
[ 84.0] Fireball crit 6496
[ 87.0] Fireball hit 3341
[ 90.0] Fireball crit 7127
[ 93.0] Fireball hit 3418
[ 94.0] Call of the Nexus fades from you
[ 96.0] Fireball crit 6485
[ 99.0] Fireball hit 3171
[ 102.0] Fireball crit 6380
[ 105.0] Fireball crit 6577
[ 108.0] Fireball hit 3052
[ 111.0] Fireball hit 3109
[ 114.0] Fireball crit 6296
[ 117.0] Fireball hit 2977
[ 120.0] Fireball hit 3122
[ 123.0] Fireball crit 6435
[ 126.0] Fireball crit 6701
[ 129.0] Fireball hit 3149
[ 132.0] Fireball crit 6688
[ 135.0] Fireball hit 3106
[ 138.0] You gain Focus.
[ 138.0] Fireball hit 3190
[ 139.5] Focus fades from you.
[ 139.5] Fireball hit 3140
[ 142.5] Fireball hit 3017
[ 145.5] Fireball hit 3101
[ 148.5] Fireball hit 3086
[ 151.5] Fireball crit 6416
[ 154.5] You gain Call of the Nexus.
[ 154.5] Fireball crit 6282
[ 157.5] Fireball hit 3438
[ 160.5] Fireball crit 7342
[ 163.5] Fireball hit 3504
[ 164.5] Call of the Nexus fades from you
[ 166.5] Fireball hit 3063
[ 169.5] Fireball hit 2991
[ 172.5] Fireball crit 6542
[ 175.5] Fireball hit 3056
[ 178.5] Fireball crit 6267
[ 181.5] Fireball hit 3171
[ 184.5] Fireball hit 3068
[ 187.5] You gain Focus.
[ 187.5] Fireball hit 3055
[ 189.0] Focus fades from you.
[ 189.0] Fireball hit 3122
[ 192.0] Fireball hit 3178
[ 195.0] Fireball hit 2964
[ 198.0] Fireball hit 3006
[ 201.0] Fireball hit 3078
[ 204.0] Fireball hit 2981
[ 207.0] You gain Call of the Nexus.
[ 207.0] Fireball crit 6519
[ 210.0] Fireball hit 3418
[ 213.0] Fireball hit 3459
[ 216.0] Fireball crit 7305
[ 217.0] Call of the Nexus fades from you
[ 219.0] Fireball hit 3139
[ 222.0] Fireball crit 6370
[ 225.0] Fireball hit 3058
[ 228.0] Fireball hit 3113
[ 231.0] Fireball hit 2953
[ 234.0] Fireball hit 3061
[ 237.0] Fireball crit 6611
[ 240.0] Fireball hit 2986
[ 243.0] You gain Focus.
[ 243.0] Fireball hit 3155
[ 244.5] Focus fades from you.
[ 244.5] Fireball hit 3056
[ 247.5] Fireball hit 3046
[ 250.5] Fireball hit 2993
[ 253.5] Fireball crit 6671
[ 256.5] Fireball hit 3138
[ 259.5] Fireball hit 3090
[ 262.5] Fireball hit 3149
[ 265.5] Fireball hit 2994
[ 268.5] Fireball hit 2940
[ 271.5] Fireball hit 3021
[ 274.5] Fireball hit 3011
[ 277.5] Fireball crit 6174
[ 280.5] Fireball hit 3391
[ 283.5] Fireball crit 7395
[ 286.5] Fireball crit 7415
[ 289.5] You gain Call of the Nexus.
[ 289.5] Fireball crit 7079
[ 292.5] Fireball hit 4015
[ 295.5] Fireball hit 3987
[ 298.5] Fireball hit 3874
[ 299.5] Call of the Nexus fades from you
[ 301.5] You gain Focus.
[ 301.5] Fireball hit 3356
[ 303.0] Focus fades from you.
[ 303.0] Fireball crit 7106
[ 306.0] Fireball crit 7129
[ 309.0] Fireball hit 3472
[ 312.0] Fireball crit 7211
[ 315.0] Fireball hit 3504
[ 318.0] Fireball hit 3507
[ 321.0] Fireball hit 3354
[ 324.0] Fireball crit 7461
[ 327.0] Fireball hit 3424
[ 330.0] Fireball hit 3499
[ 333.0] Fireball hit 3370
[ 336.0] Fireball crit 7110
=========================================
Damage: 502925 Time: 336s
Ideal DPS: 1496.8
Fireball - 115 casts
-----------------------------------------
Hits: 76 66.1% Max: 4015
Crits: 39 33.9% Max: 7461
Resists: 0 0.0%
I have a very long to do list so I'm looking for anyone interested in further developing this tool. Feel free to download the source below and play with it. See the next two for code documentation and updates.
Download the source code and current build
-
http://community.nrguild.org/uploads/DPS-Sim_Beta.zip
10/23/2007: The simulator assumes a raid debuffed target and 10/48/3 fire mage casting fireball. Procs are disabled.