Recently Karune posted a fairly large update on what's going on in StarCraft II's development. Included was information on some modifications to various units and buildings within each race's arsenal.
Quote from: Karune (Source)
Throughout the development process, the team is constantly reiterating and improving on the game in every way. As mentioned before, the Infestor too is getting a makeover, becoming much creepier and intimidating – you definitely don’t want to end up helpless at the will of this thing!
Zerg Infestor Concept Art
The StarCraft 2 team has made a number of changes in each of the races as the game gets closer to Beta. These are some of the new weapons and abilities that are currently being tested on the battlefield.
Protoss Dark Pylon
Long used only by the Dark Templar of Shakuras, the Dark Pylon is now used by all as the Protoss war for survival becomes more desperate. In addition to providing supply and giving power to nearby Protoss structures, the Dark Pylon has several unique abilities that require energy to use.
Proton Charge: an area-of-effect ability that gives all targeted Probes additional charge for their Proton-Cutters. Probes that have an additional charge gather additional minerals per trip when collecting resources. The Proton Charge lasts only a short time before dissipating.
Null Shield: a single-target ability that causes a Protoss Shield to shimmer and warp, cloaking the targeted Protoss unit. The Null Shield lasts only a short time.
Argus Link: a single-target ability that transfers energy from the Dark Pylon to any energy-using Protoss unit.
Screenshot: Proton Charge in Action
Terran Orbital Command
The Terrans rely not only on the troops they can train on the battlefield but also on troops called from deep space. The Orbital Command allows the Terrans to make use of their orbital assets to support their fight on the ground. As an upgrade to the Command Center the Orbital Command can create SCVs and serves as a drop location for collected resources. In addition it has several abilities that require energy.
Calldown Mule: sends a single automated mining robot by drop-pod that assists SCVs in collecting resources by working around current SCV mining operations. Unfortunately the Mule is still in the prototype phase and has a limited battery supply (timed life).
Calldown Extra Supplies: sends additional supplies to a targeted Supply Depot. Generally used by Terran commanders only in an emergency to allow them to support additional troops.
Scanner Sweep: using a satellite in high-orbit, the Terrans reveal a large area anywhere on the map and detect all cloaked units within the target area.
Screenshot: Mules Everywhere!
The Zerg Queen has continued to evolve over the last few months. She is a fierce defender of the Zerg Hatcheries and can often be found in small groups defending the larger Zerg infestations. In addition to defending her Hatchery from ground and air threats, the Queen has several special abilities that require energy to use.
Build Creep Tumor: with a mighty push from her bowels, the Queen creates a cluster of organic tumors that generate additional creep. In recent months the Zerg have mutated to move more quickly on creep, making this an important function for the Queen.
Spawn Larva: by injecting Queen ichor into a Hatchery, Lair or Hive the Queen can cause the Zerg structure to undergo a startling metamorphosis. The Hatchery starts to throb and green sacks swell up on the structure. Eventually four additional larva burst out of the Hatchery and land next to whatever larva are already wriggling around nearby. While a Hatchery hosts more than 3 larva, the Hatchery will not spawn additional larva, until that number drops below 3.
Razor Plague: with a great breath the queen exhales a cloud of tiny Zerg creatures that create a vast swarm nearby. These creatures attack all enemy creatures within their swarm, doing additional damage to biological targets. What makes it worse is the Zerg player can control the swarm, moving it around to attack whatever enemies he wishes until the swarm becomes exhausted and dissipates.
Screenshot: Incoming Swarm!