Hmm this is a really good question.
Keeper ... points only for wins and shutouts.
I think it would help if I knew the composition of your team, but without knowing for sure, I'll say Deslauriers. He has more opportunity, already has wins under his belt, is coming off a strong, surprisingly good season. Khabibulin is at the tail end of his career, is going to have injury or stamina issues again next season (at least to some degree) and hasn't played in forever. So for instant gains, JDD is the way to go.
Salak, albeit one of my favorite prospects right now, still has a lot of questions surrounding his future. Depends on where Markstrom goes, where Cheverie ends up and if the Panthers can move Clemmensen's salary. Don't expect him to play in the NHL for at least another year...but long-term Salak could turn into a more legitimate starter than Deslauriers. He has that potential.
Regardless, I'd go with JDD.
I'm going to say that, even if Khabibulin is healthy for next year, JDD still plays 30 games. I would imagine he could start anywhere between 30 at the lowest and 50-55 at the most, depending on Khabibulin's health. And yes, he will win enough games to be fantasy worthy. Edmonton next year could be this year's Avalanche - a good draft pick and some more solid defense will make the goaltending that much better.
And yes, 2011-12 season is totally realistic for Salak to break into the NHL for good!!
If you currently own JDD with the chance to pick up Salak, pass it up. Many times you have the chance to pick up a highly-touted prospect, but you have a good one that is more timely right now in JDD. Stick to your guns and it will pay off!!!!