Just going over what's available as a way of helping me make a decision, but I figure I'm not the only one eyeing the market excitedly.
Malkoff Quad-Core - prototype, direct-drive optic, regulated optic: thermal engineering of win, but the optics are completely hot-spot free. Direct-drive modules are custom made, and clock in at $70-80; regulated modules are the brightest thing in their weight class but also very spendy - $125 for just the module, and a quality host costs $40 or more (if you need one; off brands can be down to $20 for a host)
Can be used in a 3p, or an E1e with Valiant head. Ranges from obscene (limited prototype run on secondary market) to spendy (DD-O) to expensive (regulated P7) plus cost of host. E-hosts require $30 adapter head.
Malkoff Production Model - These may not have the raw grunt of the P7 prototypes, but they're much better behaved and much less picky eaters. They trade the 'RoomSweeper' style beam defined by an ultra-wide hot spot and wide spill for an even flood, but they're a bit more collimated than a Mule... perhaps 25° to half intensity, if I recall correctly.
Can be used in a 6p (no single-cell battery provides enough voltage) or an E2 with the VME head. Unlike the prototype, it won't need a front window due to the Cree optic.
Milkyspit's Roomsweeper - Considerably smaller, but only a sliver of reflector produces a 30° hot-spot or so. Expensive, requires a host light at $60 or more, plus $150 worth of modification.
Milkyspit's Shotgun sweeper - This variation of the Roomsweeper uses a recoil-hardened design, an MC-E emitter, and a different reflector for an even flood beam akin to the production Malkoff quad-cores, instead of the typical Roomsweeper pattern.
Chimera - This uniquely flat light is perfect for a pocket. Does double-duty as a flash memory device, and charges from USB. Also uniquely expensive at $400+. Produces an even, square flood.
Elektrolumens EDC-P7 - too big for the list, but included as the smallest of Elektrolumens' deathrays. Bigger reflector/optic for better throw. $130.
Sabrewulf EDC-P7 - Another CPF original, this starts life as a DX cheapsie, before being gutted and stuffed with the latest monster LED and a driver. Unique glow-cap feature puts a 3 mA LED under the tailcap; this replaces the tritium vials found on other high-end lights, but without the fear of little bitty glass tubes breaking. At $110 with all available options, it's fairly economical. An additional $15 buys you batteries and charger with the EDC, making it easy to get your feet wet with this one. New models include tactical grip-rings and a newly selected host.
Surefire KL-4 P7 mod - Better throw than the KL4 MC-E, somehow; using the stock Luxeon 5 driver, essentially all the properties of the original L4 are preserved, while doubling or tripling the output. Works with any E-series compatible light.
DX MC-E Budget Dropin - There is nothing else in its price class. Unfortunately, it's limited to single-cell applications, once again convincing me we need a primary 18650 cell. To quote Kramer5150,It's also capable of donating the MC-E pill to anything taking a typical China pill, including some (tiny) DX DIY hosts.First of all, my module is THE one that was tested by CPF member MrGman in his calibrated integration sphere. I bought it off CPF member bigchellis, who is buddies with MrGman and together they measured it at 150 Lumens on low and 345 Lumens on high. Note also that those numbers were registered after the module had warmed up. On a cold start it emits 385 Lumens, but it drops to 345L from heat.
This list isn't exhaustive, I know. Let's make this into a nice resource for people looking for a pocket rocket.