The Unknown Worlds Website has details on a new patch now automatically available through Steam to update the Natural Selection 2 alpha to build 152 (thanks joao). Word is: "This patch represented a large engineering effort, to make the physics, networking and hit registration work much better." Here is a comprehensive change log, and here are the abbreviated patch notes.

• Fixed hit registration problems
• Fixed various "hitching" problems
• New commander minimap, with "blips"
• New dedicated server web interface
• A dozen or so new view model animations
• Added alien "Crag" structure
• Added sound occlusion so sounds behind walls/objects sound muffled
• New marine Commander "Replicate" ability - instantly duplicates a built marine structure
• Context-sensitive mouse cursors
• Commander alerts
• Marine squads, order giving and waypoints
• Hive sight
• Much better Lerk flight
• Bullet spread like NS1
• Drifter "flare" ability that blinds marines (will require research)
• Soundscape filters when you are hurt, spectating, etc.
• Low health screen effects
• Marine power grid - Power nodes on walls power lights and marine structures. Damaging power nodes causes lights to flicker, hurting them a lot causes lights to power cycle ominously and killing them makes the lights go out for a bit, before switching to aux. power and coming back on to limited usage. Marine structures power down and stop working when power node is destroyed, and come back online when repaired.
• Added marine flamethrower
• Bullet tracers
• Skulk bite now connects more often (capsule trace instead of line)
• Reworked ns2_tram expansion, vents and lots of polish