As I posted previously, I have retired from WoW until Cataclysm. I will be focusing primarily on SC2 until then, but I'll still keep an avid eye on the priestly side of things in terms of WoW. I'll post about WoW, when there's something interesting that I have an opinion on.
Now... StarCraft, is not WoW, nor do I think that SC2 will ever be nearly as wildly popular as WoW is/was. One thing that makes WoW such a great game is that it can appeal to nearly everyone whether they are hardcore gamers or casual and WoW's the only game they've ever played. WoW truly followed Blizzard's "Easy to learn, difficult to master" motto.
By nature, an RTS game like StarCraft is going to be more competitive overall than a game like WoW simply because the point of the game is to win. There is no casual questing, RPing, making conga-lines in Dalaran, or any of that type of thing. Even in the more casual brackets, or co-op AI games... SC2 pits you against someone (or something in terms of the AI) else, and your goal is to defeat them.
If you are new to the RTS scene and are thinking of checking out StarCraft II when it's released next week, or if you are like me and love it but haven't touched a StarCraft game in 10 years, here are a few tips you probably want to remember when starting out in the SC2 multi-player arena. A few of these are race specific, but most of them are general rules-of-thumb.
General StarCraft Tip #1: Know your enemy...
...and I don't mean simply looking to see what race the other players are on the load screen. I'm talking about scouting during the match. Scouting has always been important in StarCraft (and RTS games in general) but in SC2 it's practically essential.
Scouting, aside from knowing where your rivals are located, will allow you to know what units the other players are building, so you can build your army to counter it. Scouting can also give you a heads-up about impending attacks because you will know when the other players are moving their units.
General StarCraft Tip #2: Supply and Demand.
Well... more like Supply before Demand. Keep building Supply Depots/Overlords/Pylons, and don't forget about them. Nothing can stint your army's strength before an impending attack or before attacking like having to build a supply depot before you can build more units.
Build up your supply before you're in major demand for units. Also, don't stop building simply because you have a bunch of units to attack with. This isn't WarCraft III... StarCraft is meant for huge armies.
General StarCraft Tip #3: Spend your resources.
StarCraft II is not R/L... There is no need to save your money for a rainy day. Spend those resources and continue pumping out units to build your army, expanding, or tech-ing up to try and gain the upper hand instead of just sitting on resources.
For many players new to RTS games or StarCraft, this most commonly happens while they are attacking a rival's base/expansion. The player will be tunnel-visioned on the attack and will stop production while they're focused on the attack. It's sometimes a tough rhythm to get into, but try to remember to shift your focus back to your base during an attack to queue up units to be built. This will not only strengthen your defense, but it will also allow you to go on the offensive again faster to replace units lost in your attack.
General StarCraft Tip #4: Expand early, Expand often.
Those who control the most resources, control the map... most of the time.
If you're playing at your proper skill level (which the new b.net matchmaking system is very good at) this should generally be the case. There will be games where you control more resources than the other player but they simply surprise you or outplay you. It goes without saying though, that you need resources to buy units/buildings. Without buildings and units, you cannot win.
Don't simply think that once you expand once, you don't have to do it again. You never know how long the game will take, so if you have the resources/defenses to expand.... do it.
If you have more resources than the other player, you can build a bigger army and therefore have a better chance of survival.
General StarCraft Tip #5: The Economy is your friend...
...and in a competitive game like SC, you don't want to share your friends. Sabotage your rival's economy as much as you can.
This can be something as simple as harassing their workers, or something as complex as not allowing your rival to expand. Even if you harass their workers and you don't kill any of them, sometimes that time lost where they're not mining anything, can give you the upper hand.