In case anyone was wondering if you could use the SCUMMVM project for this, the answer currently is no: http://sev-notes.blogspot.com/2009/07/steam-releases-vs-scummvm.html .

TLDR they made some very minor package changes which the SCUMM guys could easily adapt for, but they want to sit back and wait to be safe and not piss of LA in any way. I'm sure it will get patched officially or not at some point, but for now its a negative.