'Turtle Cleric' might not be the best name, but thinking about it I guess it covers a few of the key concepts:
Turtling up with a Tower Shield and blasting out party healing...protecting party members/NPCs while taking on the brunt of the melee damage. This in itself doesn't take much specialist building really, any player can try it out for themselves at low levels with an Intim item and a Tower shield.
Turtles and Clerics are known for being heavily armored, slow and vulnerable to tipping..unless they are Teenaged, Mutant and Ninja of course. Rolling a Cleric-Monk or playing caster-style with robes and caster sticks instead of heavy armor and weaponry is one way of covering these traditional flaws, though that's kind of at odds with the character concept I'm after.
In game terms this means traditional 'clunky' Clerics have to compensate for lack of speed, jump, balance and reflex saves.
-Jump and Haste Potions cover the first two (every player should grab at least 1, preferably 2/3 sets of Anger's Step before they can afford stacks of Haste potions).
-Blocking prevents the Cleric from traditional trip attacks, though against mobs such as Air Elementals it's advised to use ranged attacks or spells
-For Reflex saves...best to take cover . Cleric-Monks are known for boosting up Reflex save with Dex and gear to make Evasion worthwhile, but this doesn't work so well with the heavy armor a melee tank-type might prefer. Of course player characters should focus on sacking hostile caster mobs so that their spells don't land on the party, but a traditional Cleric is stronger at tanking melee trash mobs than caster mobs.
These might be separate builds, IMO:
IntimiCleric - A Cleric that can Intimidate mobs.
Cleric Tank - A Tank that happens to be a Cleric.
The IntimiCleric doesn't have to be a melee Cleric - could be more of a generalist or caster type that incorporates Intim to support the rest of the build. Eg. using Intim to herd mobs into killzones. At its most basic, mixing in Intimidate with party healing helps reduce the cost/need for healing - provided the IntimiCleric can take the hits as they come of course! It helps that Tower shields don't impair Clerical casting, so 'Turtle-Healing' can be effective. That's the fundamental principle of these kinds of builds: take control of the healing needed by the party, mitigate the need to revive and rebuff squishy party members/NPCs..
Post update there is a Monk enhancement Ki Shout that allows Concentration to be substituted for Intimidate skill. For Clonks that can use this enhancement the 'IntimiCleric' moniker might apply to them as well. I'm wondering about a WF Clonk I've been neglecting since Update 14 and options for 'Hate Clonk' using this method perhaps.
Cleric Tank - by definition a heavy melee type, perhaps with a deeper split, especially into Fighter and/or Paladin levels. Should be beefy, using Intim and Cleaves, as well as Divine Punishment on bosses. Unlikely to have strong casting though possible through TR benefits and gear.
My most recent foray into this area of character builds has been more of an 'Intimicleric' than a proper tank: a generalist Cleric with standard casting+healing plus some extra tank abilities with just enough Str for Power Attack, Cleave and Great Cleave. For Epic levels the intent has been to switch to a more Str-heavy build. I'm trying to get a bit more research in before going ahead and using the LR+20 on my guy.
Rolling up a new Intimicleric I didn't like how many skillpoints I needed through to pump up Intim now that we need Heal and Spellcraft..instead got interested in a Fighter/Barbarian/Cleric mutt with obscene Str. I'm sure there's plenty of options I haven't considered yet.
Anyway apologies if I haven't made the best intro post on this topic, just like to get the ball rolling and get some input on how others would build for an Intimicleric/Cleric Tank.