As other have said yes, and as others have said, sword is primarily for stats. Weapons in general are one of the best stat slots for warlocks. There are plenty of swords/daggers that raise Spell Damage by a significant portion, and usually have some Hit, Crit or Haste as well. What I normally do I carry the best Staff, Main Hand and Off Hand items I've found with me. This way, if I get a new Main Hand/Off Hand, I can add it's totals to the other that I have and see if it is better than my staff.
That being said, while we can equip the same swords as Warriors/Rogues, the stats on the swords they want are normally have Defense, Parry, attack power or expertise, stats we don't want at all. If you ever take a sword for it's DPS you are wrong, use your wand for DPS if you can't cast for whatever reason, but locks should not melee.
Edited, Nov 25th 2008 11:39am by Lathais