Enabling the widescreen in patch 1.05beta will correctly render a 16:9 image unlike before. However, the HUD will still be stretched with the patch.
Here is the game running at the standard 4:3 aspect ratio. The settings in the DoomConfig.cfg are as follows:
seta r_customHeight "720"
seta r_customWidth "960"
seta r_mode "-1"
seta r_aspectratio "0"
Here is the game running in widescreen, the settings are:
seta r_customHeight "720"
seta r_customWidth "1280"
seta r_mode "-1"
seta r_aspectratio "1"
With patch 1.05 there is no need to change the FOV setting. Just as before, increasing the FOV setting adds horizontal and vertical information to the screen, producing a distorted image. In the above pics you can see only horizontal information is added, meaning widescreen mode is working correcly. However, note that the HUD remains stretched, even with the patch.