In light of Double Fine's recent success with Kickstarter, I'm wondering if Telltale would be up for a Kickstarter pledge to raise whatever funds are necessary to code / port / update Sam and Max Season One so that it runs on OS X. This way you'll be able to gauge if there really is a market for the project and you won't lose cash undertaking the process.
You can even keep the pledges simple: twenty bucks for a copy or key to the game, and / or a way to contribute to the update and buy the complete series in the process. (I'd also suggest that the purchase could work with Steam.) No t-shirts, no posters, no soundtracks. Just a copy of the game, prepaid.
I have no idea how much it would costs for you to take on someone solely for this project, so that you're not taking people off your more pressing works. But I'd love to put my money where my mouth is and pay up front, just so the damned thing gets done. And hopefully, so would a few others. At least enough to break even.