So I like dominion, I really do; but it needs some serious work. Starting with the new skills you get. Essentially, they both suck.
They need to be tweaked to be useful, like the turrent one preventing turrent captures for the duration of it; or something more potent for defense as it is usually all but worthless on anything but offense.
The range of the towers are extremely small, to the point unless you are sitting inside the tower against a melee hero it won't actually really do anything. Furthermore, the capping of towers needs some serious work; the fact any one person can attempt to take a tower and prevent it from helping defend while a hero is trying to defend skews the balance to cc heavy teams as they can easily stun the defending team but still attack at no penalty because someone can be trying to cap the tower. If a person is defending a tower inside the stone zone there needs to be something to promote defense; either some kind of defense buff or the prevention of the tower being cappable, or something. Not to mention, the damage on towers can also be easily negated with a little health and defense stacking further promoting a "run-n-gun" all offense type of show.
Now to minions; I honestly don't know why you put them in dominion since they are absolutely worthless. Not once have I seen a minion contribute to either a capture or a kill. They come in such small packs they are easy to beat back, and since the lanes are always visible it makes "pushing lanes" all but impossible because you are easily ganked and seen trying to push.
Essentially what I'm saying is, i'd like to see more focus on the points actually promoting defense, and a bit more dimensions added to what seems to be a 1D game mode (zerg rush the nodes and if you have 1 person more just dive in, kill the defender(s) and take the node). Possibly lengthen the time on taking down nodes to promote staying there and defending; or delaying the time for each hero around the node. Something to promote defense and not just running to every empty node and just capping it before moving on to another.