This is a list of some current speed tiers. There are very helpful when determining EV spreads and the like.

(Credit goes to this site for the original copy)

692 - +2 Jolly 252 Terrakion
524 - +2 Jolly 252 Cloyster
519 - +1 Jolly 252 Terrakion
518 - +2 Modest 252 Venusaur
498 - +2 Bold 44 Bulky Volcarona
496 - +1 Naive 252 Landorus
492 - +1 Jolly 252 Jirachi / Salamence / Volcarona
486 - +1 Timid 252 Hydreigon
478 - +2 Adamant 252 Cloyster
447 - +1 Timid 252 Rotom
417 - +1 Timid 252 Heatran
394 - Timid 252 Jolteon
393 - +1 Timid 252 Politoed
391 - +1 Adamant 252 Gyarados
388 - +1 Adamant 252 Dragonite
373 - +1 Bold 44 Bulky Volcarona
372 - Timid 252 Alakazam / Dugtrio
364 - +1 Jolly 252 Tyranitar
361 - Timid 252 Starmie
360 - +1 Timid 252 Magnezone
354 - +1 Jolly 252 Scrafty
353 - Timid 252 Tornadus
350 - Timid 252 Espeon / Gengar / Latios / Latias
346 - Naive 252 Infernape / Terrakion / Virizion
339 - Naive 252 Mienshao
331 - Naive 252 Landorus
328 - Naive 252 Salamence / Celebi / Ninetales / Volcarona
317 - Jolly 252 Acrobat Gliscor
306 - Timid 252 Lucario
298 - Timid 252 Rotom W
295 - Modest 252 Hydreigon
293 - Adamant 252 Haxorus
284 - Jolly 252 Mamoswine
279 - Adamant 252 Lucario
278 - Timid 252 Heatran
270 - Calm 136 Sp Def Ninetales
269 - Adamant 252 Toxicroak
261 - Adamant 252 Gyarados
259 - Adamant 252 Dragonite / Mamoswine
249 - Bold 44 Bulky Volcarona
244 - Bold 32 Celebi / Jirachi and Impish 72 Gliscor and 144 Rotom-W
240 - Timid 252 Magnezone and Bold 16 Tentacruel
239 - Adamant 252 Breloom / Politoed
236 - Jolly 252 Scrafty
230 - Calm 160 Heatran
229 - Adamant 252 Scizor
206 - Adamant 0 Bulk Up Toxicroak
191 - Careful 60 Bulk Up Breloom
190 - Calm 0 Sp Def Heatran
183 - Bold 108 Jellicent and Adamant 100 Tyranitar
182 - Impish 24 Skarmory
177 - Modest 44 LO Vaporeon
176 - Adamant 0 Metagross / Politoed / Skarmory
169 - Bold 52 Jellicent
168 - Adamant 8 Scizor
166 - Bold 0 Vaporeon
158 - Adamant 0 Tyranitar
152 - Careful 0 Bulk Up Scrafty
146 - Bold 0 Blissey
142 - Sassy 0 Mixed Tyranitar
136 - Bold 0 Chansey / Donphan
126 - Adamant 0 Conkeldurr
116 - Impish 0 Forretress
114 - Calm 0 Gastrodon
96 - Bold 0 Reuniclus
76 - Impish 0 Ferrothorn and Relaxed 0 IV Forretress
58 - Quiet 0 IV Trick Room Reuniclus
40 - Relaxed 0 IV Ferrothorn

(This may be subject to change in the future, when Pokemon get promoted / demoted on or off this list.)