I recently acquired a mac Mini and was playing around with it trying to get the myth front end to work. While i haven't given up on that, it got me thinking if there was a simpler way.
I already can mount and access my shows via Samba, and can view them using VLC ( since quicktime will not recognize them). I came across this neat app called MediaCentral
http://www.equinux.com/us/products/medi ... index.html

It is not a flashy app but it will access and play the videos and recorded tv shows.
What I did was:
1) Set up the samba share so it will mount automatically
a) This is done by setting up samba, good walk through on Knoppmythwiki
b) Logging in by selecting from the menu in finder GO -> Connect to server, enter the address to your server as follows

smb://MythBox-NAME;mythtv@IP-ADDRESS/myth

a dialog box will popup. enter mythtv for the user and password click on the save to keychain button. (I remember there being a problem with this in 10.3, where the keychain would not remember the user name. it has been fixed in 10.4)
this will mount the MYTH share on your desktop
c) Add an alias of the Pretty and video files to the Movie folder in your home folder.
d) Download install and launch MediaCentral. Choose video from the selections and it will follow the alias you made to the samba share and give you access to all of your shows.

Pros:
+Easy to set up
+Will mount the share for you if set up properly ( keychain settings correct)
+show the shows and movies listed in those folders.
+It is Distribution independent. (this i think is my problem with mythfrontend)
+Plays things not on the mythbox, podcasts, vidcasts, net radio (though these can be added to your Myth system)

Cons:
-It is not MythFrontEnd, so you will not have as many options, just video and prerecorded TV.
-Does not recognize commercial skip commands.(real bummer)

Future:
I saw a modified Pretty script that put the shows into subfolders. this would be helpfull in navagaing the TV catagory.