Sigaty notes that the overheating vespene gas mines mechanic from Blizzcon 2008 made "gas mining way too frantic," and hence that mechanic seems to be gone (I don't do a lot of micro-management, but I didn't notice my vespene gas refineries overheating like at Blizzcon); he also notes that the Baneling, the Zerg suicide bomber, was having an identity crisis until the team settled on making it a fodder-unit killer, as opposed to a building killer. The economy-boosting decisions that Sigaty describes also serve as a pretty good example of StarCraft 2 overall: a lot like StarCraft, but with enough changes and tweaks to feel fresh and challenging. For every classic trick that still works -- be it Zergling or Zealot Rushing -- there is either an all-new unit or a change to an existing unit that gives you pause, and makes StarCraft 2 feel like a legitimate sequel and not just a graphical update. For example, one of the new Terran units is the Hellion, which is a flamethrower-equipped dune buggy; or, in the language of the original StarCraft, a firebat and a vulture smushed together. The Terran Scout unit is now something that can take out Zerglings and Zealots very quickly and then safely retreat. The Medic and the Dropship have been combined into the Medivac Dropship -- resulting in a transport that also increases the livelihood of your on-ground infantry. And the Protoss can now turn their gateways into warp gates, which then allow them to instantly beam-in infantry anywhere the Protoss player has established a Pylon (especially useful when sneaking in the new Warp Prism unit and converting Warp Prisms into Pylons behind enemy lines, which creates a fast and easy ambush)
A more personal example of a StarCraft tactic that not only still works (when I play against non-awesome or -competitive players), but is actually better in SC2: In one match, I used my general Zerg strategy of not rushing, but instead, lasting long enough to advance up the technology tree and use air superiority for victory. In the olden days, that meant massing up lots and lots of Mutalisks and Guardians, and having them pummel the crap out of my opponent. For SC2, my Zerg air force consists of Mutalisks, Corrupters, and Brood Lords. Mutalisks are still general "air guys who can hit anything", while Corrupters are anti-air units that convert their targets into temporary allies (when the Corrupter's victim dies, it turns into a "corrupted mass" that serves as a short-lived turret), and Brood Lords are the new-and-improved Guardians from SC. While Guardians were long-range bombers that spat globs of acid onto hapless fools on the ground, the Brood Lords one-up them by spitting out Broodling eggs -- upon impact, two Broodlings pop out and start wreaking havoc during their brief lives. If you carpet-bomb your opponent with multiple Brood Lords, you create utter chaos with tons of little Broodlings running around, biting and clawing whatever they get their hands on. A Blizzard employee quipped that the Brood Lords are like, "...dogs with bees in their mouths. And when they bark, they shoot bees at you."
Again, the beta seems close; Sigaty and team want to go online ASAP. "I'd want this beta to go out tomorrow," he quips during our June 22 interview. But, we have to let the development team put enough polish on Battle.net to deem it fit for the rest of the world. All I can say is, the wait will be worth it when the beta finally arrives. And when it comes, take the time to pay a little bit of attention to how units die. "We recently completed all the 'burning death' animations for all the units; every unit has a unique death animation depending on what killed it. I wonder how many people even notice those." When you're finally playing the StarCraft 2 beta, take a bit of time to note and appreciate the ways different units get burned, blasted, stabbed, or melted to death.