if you havent looked at the front page for a preview of 1.04, check it out!
heres an interesting one - "siege cannon targets now must be sighted to be hit (in view of friendly player or scanned by commander)"
now at first i thought, "yay no more lame sieges in vents", but then i realized this can actually be a marine advantage. right now a siege cannon shoots other buildings before it goes after the hive, but all a commander has to do is scan only the section where the hive is and avoid going after all those defence and offence towers first. PLUS a commander can have his troops build many siege cannons that dont shoot right away, alarming the aliens. so he could have 5 cannons go off at once instead of 1 at a time and alerting the aliens and getting swarmed.
"I don't drink, I play video games."