The JAVA port of DOSBox developer danoon has been experimenting with incorporating parts of WINE into his jDOSBox. He has managed to get some Win32 games to run in jDOSBox. Here is Caesar III
running in a browser. http://jdosbox.sourceforge.net/beta/c3.html
And Full Tilt! Pinball
DOSBox perfectly fills the need for the vast majority of the DOS games, but there is not yet a reasonable solution for the old Win games that refuse to run on modern Windows. It is easy to install Win3x in DOSBox and works fairly well for the old Win16 games and there is VM software that you can install Win9x in. You can even install 9x in DOSBox, but there are drawbacks, such as no CD drive access and it is not officially supported. One of the biggest drawbacks to any of these is you cannot distribute anything with an earlier version of Windows installed in it. I can't use it in one of my installers nor can anyone distribute a pre-configured VM for those without an earlier version of Windows or who find setting up a VM a daunting task.
DOSBox with WINE incorporated into it could be a great cross platform answer for the old Win games. It would be great to see someone take on this task with regular DOSBox. Perhaps it would be best as a fork, as I certainly would not want to see any compromises to the high compatibility that DOSBox now has with the vast majority of DOS games.