Will Porsche win LMP 1 at Le Mans this year? It depends. Lots of factors at work here. I think a lot of the factors come from inside V.A.G. The call was made back in 2003 to let Bentley win in their last year running the Speed 8:
Bentley Speed 8 - Wikipedia, the free encyclopedia
Will this happen for Porsche in their first year in LMP 1? If you see a few Joest team mechanics working on the 919 this year in the pits... yes. Otherwise I think this is just a learning year. Understand the car and the technology at speed for a full assault in the coming years.
But...when you read about the Audi R18 for 2014, you see that it is more an evolution of last year's car. That could be telling also. Why heavily fund a car you want to run in 3rd or 4th place.