Hooray for a better GNS3!
The new release (finally) supports relative paths, but does not save the .net files as such. Still, being able to at least open a .net file with relative paths for the working and config directories is a huge step in the right direction. And of course, if you don't save a topology that was opened with relative paths in the .net, GNS3 will make no effort to change this, allowing you the opportunity to pass the lab on to someone else without reintroducing new, absolute paths. Now I just need to think of a convenient way for everyone to use their own image directories without making them perform a search-replace.
The other thing I really like about this release is smooth zooming. Before, you could never really find a zoom level that worked. Having too much or not nearly enough space at the margins of devices was a fact of life. Now, though, a very smooth zoom with acceleration is employed, making me wish people like M$ would apply the same idea to Visio and other useful software. In fact, the zoom feature is seamless enough that, for larger topologies, I feel very comfortable zooming in and out throughout the life of a lab, rather than being OCD about how the topology is framed after working so hard to get every router and note on the screen.
If you're interested, the guys at GNS3 actually saved me the trouble of doing a how-to: http://blog.gns3.net/2010/03/how-to-run-gns3-on-mac-os-x/. I used the process titled "Method 1" and had no issues along the way. You should expect approximately 90-120 minutes of your life to be wasted depending on compile and download times. The main period during which you'll want to make some coffee is during the download and compile of PyQt4.7.