Scott Ritchie, an Ubuntu MOTU, has proposed that WINE
be moved into Ubuntu's Main repository thereby making it shipping with Ubuntu by default in some form. This proposal is coming after he and several Ubuntu developers had discussed this idea last week at the Ubuntu Developer Summit. What he is proposing is that by default on new installations of Ubuntu, when clicking on an Windows executable file to come up with some prompt informing them of the possible actions, and then to setup WINE by default.
In order for this to make its way into Ubuntu Main, Scott first has several areas he first wishes to see improved within WINE. Some of his action items including the ability for GNOME to be able to read program icons embedded into an executable, various new menu systems for GNOME/WINE, and a centralized system for displaying transparent messages. In addition, there are a number of packaging changes that will be required for 64-bit WINE entering the main Ubuntu repository.
You can read more about Scott's wishes for Ubuntu and WINE on the ubuntu-devel mailing list
and on his Ubuntu Wiki page