Hi there,
I just found out that Araxis Merge (IMHO one of the best merging tools available, and the only program that makes me miss Windows sometimes) is coming to the Mac platform.
The current beta is quite nice, has AppleScript support and includes commandline tools for automation.
So... is there any chance of having the Subversion.tmbundle crew take a look at it?
Hopefully you'll instantly fall in love and add support for it as a diffing/merging tool : )
More info, and download at http://www.araxis.com/merge_mac/
Thanks in advance ; )