I think the ease of use under Windows is a very temporary thing - it may change with the next version of Windows or even with the next service pack for Vista or 7. Knowing that the thing runs in DosBox is a nice thought, too bad GOG.com does not ship DOS files with their release of the game.
At any rate, I successfully converted my GOG.com Fallout installation (for Windows) by downloading the Fallout 1.1 DOS patch, then copying dos4gw.exe, hmidet.386, hmidrv.386 (for memory) from other games I have to the fallout folder (FO1 is supposed to have dos4gw v1.97), and some manual tinkering with fallout.cfg to set up the sound because sound.exe, which was apparently used to set up the sound in the original DOS version, is nowhere to be found legally in either the Win edition or the official patches. I got it to run under DosBox 0.74 - I had to set memsize to 32 to get it not to crash after the first "loading" screen, otherwise it then ran perfectly at full speed.