I was able to install the North America maps on my Mac straight off the DVD.
The Garmin Bobcat software (Mapsource for Mac I guess...) has a nice UI and all but it's not totally stable, I've had a few crashes, remember that it's still a beta version.
The "not stable" part is less annoying than the lack of features. When routing I find I have to add a waypoint then insert the waypoint into the route. The software will not let me drag a route segment to pick a different set of roads. Frustrating. But I use it.
Until recently I was routing with google then using GMaptoGPX to save the route then use GPSBabel upload to the GPS. However, GMaptoGPX didn't work for me the last two times I tried to use it.
+3. I'd love Mapsource for Mac....
I have an old Dell Laptop that died. I 'invested' 50$ in a replacement drive specifically to run Mapsource. I create all my routes in Mapsource and download to my GPS. I've been creating routes for 3 years now and I have to keep some sort of PC alive to use it.
A friend of mine uses PC emulation software in his mac with satisfactory results.
With MapSource for Windows installed on my Boot Camp partition, I ran the Garmin MapConverter in Windows. MapConverter duplicated the existing maps from the Windows MapSource installation into a folder of my choosing.
The City Navigator North America, Mexico, and Brazil maps together finished in ten minutes. The Canada topo map took 30+ minutes to convert, and the US topo is still converting.
After installing the Garmin Mac apps in the list above, I navigated to the converted maps on my Windows partition from within OS X. The "gmapi" files displayed with a Garmin icon, and double clicking one opened the MapManager app which promptly asked for confirmation to install the selected map.
After the installation succeeded (in less than a minute for City Navigator Mexico), I quit MapManager and ran Garmin RoadTrip. The new map appeared in the maps select box at the top right. Whoa-la! Mapsource for Mac.
Read a review about Garmin RoadTrip as compared to MapSource. You won't be doing in RoadTrip what you did in MapSource any better -- but it looks pretty.