The 10 games from LucasArts that I posted about yesterday are now up on Steam. The games all come with their own updated Windows executable, and don't use DosBox or ScummVM. Some of their datafiles are now embedded in the EXE as well, as noted by bgbennyboy on the International House of Mojo comments section. So, they won't run in ScummVM.
But, Indiana Jones and the Last Crusade, Loom, Indiana Jones and the Fate of Atlantis, and The Dig are now available for the first time in over 10 years, so that's the most important thing. LucasArts also mentioned they are going to be announcing more Steam releases in the future, so here's to hoping their entire back catalog of adventure games will become available again in one form or another. :)