There was a poll earlier in the year to see which game would get the Mac port first. Sam and Max won, but there was a big battle between it and SBCG4AP.
The Season 2 Mac ports were only released recently (i.e. about a month ago) so I'm sure that th Season 1 ones will show up sooner or later. Possibly later rather than sooner, considering there's at least 4 games series in development right now...
(S&M:TDP, NT:PA, BTTF, JP)