[Theleb]

You can gem for significant amounts of haste pre SWP but generally you won't achieve any greater success through that method than you would with crit/damage - there are a couple of items that are perhaps worth picking up (Staff from Illidan, BT Trash ring, ZA ring from third chest, potentially the S4 neck) but I would definately advise that you check against suitable other items (A MH/OH combo, Neck from ROS etc) before going for haste in any slot to see how much of an upgrade it is.

If you're looking for +hit gear there's a lot to choose from - check out Canadianpimp's Warlock Gearing guide for a really comprehensive rundown.