So far McLaren has shown little interest
Only on the outside...
As far as the technical regulations meeting that took place Toyota and other manufacturers seemed to be making themselves look interested.
Toyota is coming back with a Dome/Factory hybrid petrol, that's a fact.
Nissan could be getting more serious, possibly Leaf battery tech in a V8 petrol hybrid.
HPD may also be returning with a P1 Wirth coupe.
Peugeot won't be going anywhere.
Same for Audi even with Porsche.
The king returns in Porsche for 2014.
Ferrari, oh yes. P2 coupe run by Risi

.
And the FIA will run the WEC.
This is garbarge, completely. No, the FIA will not run the WEC, that's what the ACO will be doing. The FIA is only involved in name as the FIA controls the 'World Championship' name series' like the Intercontinental Le Mans Cup (average Joe would have absolutely NFI what the ILMC is but an FIA World Endurance Championship would create instant interest) want and need. The ACO wanted to call the ILMC a World Championship but needed the FIA onboard to be able to do so.
The engine regulations for F1 will have plenty in common with LeMans tech. Energy recuperation, not the flimsy KERS, turbocharging, V6 engines, fuel flow limitations- all discussed within LeMans as well. Engines now last 4 races, practice sessions, qualifying sessions. To say they wouldn't last 24 hours is a bit premature depending on how the ruling on the future engines will play out in F1.
An F1 engine revs out to 19/20k rpm and is designed for the shorter races, no matter what teams say they still need a rebuild after every race. Energy recuperation
is KERS (Kinetic Energy Recovery System)...it'll just be opened up at some point to allow other forms of energy recovery (waste gases during off throttle periods where the turbo spins a generator).
V6 engines really has nothing to do with there being a link between Le Mans and F1, V8 is where it's at for reliability (yes, except for the kings of reliability Audi) and there's no chance of it leaving sports prototypes.
F1 will have nothing to do with Le Mans in 2014 other than some shared tech (like energy recycling systems). 2014 will see almost a return to Group C days where the rules are opened up and fuel economy is the name of the game. We'll see teams given a certain amount of fuel to get thru the race (2000L for diesel, 3000L for petrol roughly) and this will open the way for hybrids to rule the LMP categories.
Please, leave the F1 talk where it belongs...and that's
not in sportscar racing.