@Tennisace: I agree that a fast Taunt is more useful than a slow Taunt in most circumstances, and Colossoil has indeed made an enormous impact and shifted the entire CAP metagame in an offensive direction. However, a defensive Taunt like Rev's, aimed to prevent setting up from viable switch-ins, and an offensive one like Colossoil's, aimed to prevent healing, Phazing, Spikes stacking, etc. so it can muscle through defensive threats, are two very different things, imo. The comparison between Taunt Revenankh and Taunt Colossoil (and Taunt Gliscor and Taunt Gyarados) becomes more relevant the further you push Rev's speed, yet there is no way it will become a "better" Taunt user against stall. It'll still be good, just not as good. However, in terms of being a Taunt user for stall, Rev could be incredibly useful and may help give stall a fighting chance of a comeback on the CAP ladder (being able to deal 72.06% - 85.29% to 4/0 Colossoil with a 0 EV, +0 Cross Chop/Hammer Arm is a huge plus, as well), something it does not need tons more speed to do, imo.
As I said before, when you think about a specific set for a specific Pokémon (in this case, Taunt Revenankh), you have to think to whether or not a particular set is outclassed. Pokémon is a game of niches, and if a Pokémon does a specific niche better than you, you must move somewhere else.
So, what about Taunt Revenankh? LEt's see which could be the possible uses (and competitors for the team spot) in the CAP OU metagame.
As an offensive Taunt user? You said it, Colossil outclasses him. Hell, even if you depended on Revenankh for a stallbreaking Taunt user, Colossoil is still better offensively.
As a defensive Taunt user? Well, Revenankh has three things to do as a defensive Taunt user, which are: Spinblocking, Bulk Up, Defensive check (i.e. something meant exclusively to wall and taunt some threats). As a Spinblocker, you do not need Taunt. As I said before, the only spinner you could think Taunting is Forretress, since Fidgit and even Tentacruel are too fast anyway. If you are really that concerned about dealing with Forretress (I really cannot think of any more reasons you would need Taunt if what you need is a Spinblocker), just use a Fire-type move and you are done for. Forretress is also so slow that Revenankh would outspeed him even at his pristine 65 base Speed.
As a setupper, I already said it too, Gyarados does the job better. Hell, even if you put Taunt to get past Arghonaut (which I think is the main reason why some of you want to increase Rev speed to into the 75-80 region), Gyarados does that same, exact thing better. Gyarados also has to worry less about things like Metagross and Starmie since, thanks to Dragon Dance, he can outspeed them whereas Rev is at mercy of them (and also Togekiss and Zapdos I may add).
The defensive check in general is probably Revenankh's best bet. However, unless I specifically need Rev's typing and/or stats (and if that is the case, probably I'd go with the ShedRest set anyway), Taunt Skarmory (for example) is better, since at least it can do something else (namely, spikes) rahter than sit down and wall stuff.
Bottom line is: if you want to use Taunt Revenankh as a spinblocker, you do not need the extra speed, but rather extra bulk, if you want to use Taunt Revenankh as a setupper, use Taunt Gyarados, and if you want to use Taunt Revenankh as a Taunting wall in general, use Skarmory, Gliscor or something else. Some of you may call this argument too brief for thaeir taste. But even if I go on and spend two pages of the thread to explain in detail how almost every specific use of Taunt Revenankh is outclassed - and how those who aren't strictly outclassed either do not require extra speed or perform mediocrely compared to standard ShedRest or to other Pokémon in the tier - the conclusion would be the same: using the (let's call them this way) "extra BST points" to raise Revenankh's Speed (sometimes hell, even at the cost of lowering its bulkiness) is the wrong way to go with the stat spread revamp.
The reason I submitted this spread was to potentially help Rev be better (as I saw it) at its "job" of Spin Blocking and abusing Bulk Up by allowing it to better switch in on, stay in against, and force out OU's Rapid Spinners and to better deal with offensive threats that like to switch in (without dramatically toying around with its stats). To fill the void left by Rotom-A, I felt that it should focus on defensive additions to better deal with the Colossoil metagame. Taunt was on my mind, yes, when making it, but it wasn't my only consideration. Sure, it still can't switch in on LO Colossoil, but they don't typically run RS anyway, so it doesn't have to, and if 'Soil has to start running Rapid Spin to beat stall, then that's a coverage move or a Sucker Punch or a Selfdestruct it can't abuse any longer. An excellent, more offensive spread that can better abuse Mold Breaker or run anti-bulky offense with Taunt is already available in Deck's 90/105/85/65/95/90 build, which is why I didn't submit something with the kind of Speed you're talking about.
Sorry, but if Revenankh cannot switch into Colossoil just like Rotom (as you admitted apparently), how is adding Taunt helping Revenankh filling the void left by Rotom (besides the facts that Rotom isn't "disappeared" at all and that Taunt is completely useless against Colossoil as you said). Also, that spread of Deck Knight you highlighted is horrible in my opinion. Not only it diminishes Revenankh's bulkiness (which is crucial for the main ShedRest set), but it completely bastardize Rev's selling points as a Spin Blocker (namely, his ability to come in repeteadly and Resting off the damage very fast thanks to Shed Skin) for a bad middle-ground spread which cannot make up for the loss in Defenses through the enhanced Speed (for reasons I explained above).
@ ZystraL: seeing as most Rev don't run Atk EVs, I'm not sure how many "free" EVs it'll have from there. Adding to HP and not Def/SpD is just a reorganization of the same stats, so I'm not exactly sure what you're saying there. I mean, you can have a small range of base stats for every stat and fart around with EVs to get the same overall numbers, so it really depends on what you think should be the higher "maximizable" stats. Based on your post, it appears to be HP. Do you have a particular spread in mind besides your 90/105/88/60/100/87 spread? You should submit it.
At least, HP goes towards enhancing the strong points of Revenankh.