I actually did a poll on the subject over on the teamxbox forums and 88% of respondents said they'd buy classic adventure games as is (62%) or with graphical enhancements (26%). Only 12% expressed disinterest.
http://forum.teamxbox.com/showthread.php?t=580061
[And, yes, I was banned from the TXB forums as you may notice in this link. Not because I actually violated any TOS, but because one of the members who disagreed with me had a moderator he was friends with issue a wrongful banning on my account; apparently it was his only way to win an argument.]