+Sta is important when your stuck with old world gear in which you're having to choose "do I want Sta, Int, Sta+Int, OR +Dmg?" Sta is the best choice here because it relates to HP AND Mana, which then allows for longer DPS output.
Once you get into OL you'll find not only great Rares and Epics with all the STA you'll need AND damage options, but also green gear like "of the Sorcerer" which has inordinate amounts of STA already on it, AND has the +dmg/Int.
For high-end raiding though, things are different.
+Hit makes it easier for all your offensive spells to land. Think of it as boosting your effective level when casting your offensive spells. You're never gonna hit those level 72s with already high resistances w/o some +hit, and if you're not hitting the enemy half the time, then it really doesn't matter how much +dmg you have.
Spellhaste is obviously useful for boosting DPS, although like it was posted up here it's not going to be as effective for a Lock, and especially for an Affliction lock. The reason, I believe, he put it in this order was to illustrate the fact that Spellhaste is much harder to come by than +Dmg, so if you have a piece of armor and you're trying to figure between 1 with Haste and 1 with +Dmg, it may be better to take the Haste.