Hi, I'm a new member, and I must say that its great that you're bringing support to the mac. I'm a big fan of both macs and adventure games, so thank you so much!

I am running OS 10.3.9 on a G4 400. I downloaded the latest beta, and having read previous posts, I figured that Allegro probably would not work in this case. So I compiled my own embeddable Allegro framework and placed it in the application bundle (renaming the old one). I tested it with Apprentice (I'm completely new to AGS and that caught my attention) and it worked! Well, mostly. It seemed to load and run fine, but there were a couple of problems.
First, the hardware cursor was stll being displayed, in addition to the software one (in this case a wand). It presents no problems that I've seen in therms of gameplay, but it can be somewhat annoying.
Second, the game crashed when I tried to leave the room.
Purely by accdent, i discovered that I was able to leave the room by using the look command at the staircase and not the walk command. I also noticed that when it did crash (using walk), it crashed before the character actually went down the stairs (if you would like, I can try to provide a screenshot of where it is). I was able to use the walk command to go back up the stairs just fine, but walking down a second time would crash again.
I was also able to exit the second room to the outside fine. Outside, I found that I could not get back inside. No matter what command I used, the character would go in the door, the screen would fade like it was changing scenes, and then he would appear outside again, in the position that he was when he walked outside for the first time (not at the doorway where the screen faded).
I haven't tried any other rooms yet, or any other games.
Actually, I don't know if the Allegro framework that you bundled with the game works on Panther or not, I never even tried it (I already had the Allegro source compiled, so I tought I might as well install the embeddable version, because it would take so little time). If you would like me to, I can easily switch the folders back. Also, if there's a different game that you would rather me test, I'll be glad to do that too.
I hope this helps in any way!

-Dan
P.S. Feel free to PM me requesting my email if you would like, its probably a more reliable way of getting in touch with me than this message board