The NPatch makes several enhancements to random maps like enabling a new terrain set, a new battlefield type and even the ability to add urban areas.
Creating Desert theater maps has been enabled. This has yet to be improved however, since you are still unable to specify lighting settings in rmgmd.ini.
The formerly disabled Archipelago map type has been enabled for use in the RMG. An archipelago map that has many small islands, including one for each player that has resources and room to build.
The RMG can place urban areas onto maps again, just like in Tiberian Sun! This is only for inland maps at the moments as the rest have not been fully tested. A simple checkbox on the RMG menu has been included for toggling these areas. This can cause an IE with snow maps however, if you lack the Median fix.
Westwood seemingly forgot an important change from Tiberian Sun that, if you attempt to place urban areas on a snow map, the game will invariably crash. The fix is simple at least.
Open snowmd.ini then add Medians=71 to the [General] section of that INI. This fix is included with the patch, but if, for some reason, you require a modified snowmd.ini, you will need to apply this.
At this time, urban area placed civilian units and structures are hardcoded to a select group.