From looking at the screenshots, it seems great for choosing which parts you want to include in your finished DVD... something DVD2oneX doesn't seem to do (unless I'm very much mistaken or I've got an old version).
Anyone know of any app on OSX that does the same job???
DVD2oneX will, I believe, do the same thing DVD Shrink will do.
Unfortunately, DVD2OneX, is crippled until you purchase a license. (I avoid this type of crippleware as it doesn't follow the spirit of shareware--make a great app at a great price and people will pay for it, voluntarily.)
Anyway, if you have a copy of VirtualPC you can use DVD Shrink to shrink dual layer DVDs.
I use DVDBackup (MacOS X) to rip and unencrypt the content and DVD Shrink to make it fit on a single DVD. Then use Toast to Burn the DVD.
For single layer DVDs, of course, you can skip DVD Shrink and VPC altogether.
DVD2oneX will stop burning after half an hour. But I highly recommend that you purchase this software because it really rocks! Use DVDBackup to decrypt, DVD2OneX to shrink and toast to burn! Works perfectly for me!