Ability to install on a flash drive without leaving any needed files behind.
I could try doing this myself but i dont know how so a few pointers would help.
You can copy the new Wine.app bundle to a flash drive. This allow you to take the program anywhere and you can run Wine off the drive.
Copying Wine.app will not take any Windows programs you later installed, since they are all at "Home/.wine/" but you could copy those to the new computer. I could have placed those inside the App, but decided against it to make it easier to delete personal files/programs and prevent accidentally transferring these to someone else.