Looks like you'll have some rebuying to do if
this news article has any truth. Those two big reasons you originally listed are a thing of the past. Time? Pah, we're in 2010, anything is possible. Money? We all know how successful Monkey Island was/is.
"We have it from a very reliable, confidential source that Telltale Games may be planning to release its entire lineup of games to Macintosh very soon, possibly next month (February 2010)."
Maybe. Depends how reliable that confidential source is.