After messing around the last couple days trying to add widescreen support to this game (with limited success), I Googled it and discovered that Ken Miller, one of Battlezone's original programmers, has recently begun spending some of his time writing new builds that not only solve some compatibility problems, but even add widescreen support.
You can track the progress and download the latest builds on the
Battlezone1.org forums. It certainly isn't flawless (many of the higher resolutions will crash the game when returning to the menu for example), but it's still a must-have for anybody who's a fan of this game.
Anecdotally I can confirm that 1440x900 does crash when returning to the menu, but 1280x720 does not.