If features are going to get their own script, you should be able to create features that, are not defined by the map but a mod. I can think of some good uses for these, and considering some one is going to go to the trouble of scripting features, it should be flexible.
For instance, what if a side built a feature that, say spawned units for them every X seconds or something to the like. Features could be scripted to change what they rez into based on the unit(s) around them perhaps :), allowing for "special" units that can only be rezed either by a certain unit, from a certain feature, or both together. Units could be made to "resurect" themselves after a certain amount of time (watch as the krogoth rises from its wreck

. And a whole host of other life after death crazyness.
Perhaps moving walls could be created that patrol an area? getting in the way of all who they come across

.
Features could become weapons and utilities when having units preform such tasks would be inapropriate, or impractical.
just a vouch for flexibility and utility