I understand the notion that Okafor is a bit redundant with the bigs we already had. But I don't think it's completely true. We needed better rebounders. Okafor is an excellent rebounder. He also will allow Nene to play more PF, which I believe he's a slightly better fit than he is at C.
Okafor is also an incredibly intelligent and well-spoken individual, especially by the NBA's standards. He seems to be a very hard worker and a capable leader. Those types of traits alone aren't that special, but when you combine them with legitimate talent, then they're quite valuable. I like the culture we're building. Especially considering what we went through with the knuckleheads for the last decade it seems.
I also like it from a depth standpoint. Injuries happen. And injuries seem to happen more often to the Wizards (I don't actually believe this is the case, or at least that it's more than a coincidence and some bad luck, but many of you guys seem to). Let's assume Blatche is amnestied or traded. We have Okafor, Nene, Booker, Seraphin, and Vesely in the front court. If we didn't acquire Okafor, we'd have a solid 4 man rotation, but when one of them goes down with an injury (it's inevitable that it'll happen at least somewhat at some point during the NBA season). Now 5 quality players might seem like a logjam of sorts, but when an injury happens, we'll be fine. More than fine. I like that. I also like that our front court's new depth will make future trades easier to complete. We have so much flexibility because of our depth. Not only do we have 5 players in the front court alone who are decent assets in a potential trade, but we could now very easily pull off a trade that sends 1 of our big men for 1 wing, straight up (or close to it, I guess).
We had good big men already. Now our big men are slightly better. We didn't have good wings before. now our wings are sliiiiightly better, but still a big weakness. Let's say we still want to acquire another decent wing. If another team has a surplus of wings and a lack of big men, guess who makes a great trade partner all of a sudden?

Before we could maybe traded somebody like Booker for a decent wing (in theory). But if we did that then we'd only have 3 decent big men in our rotation. But now we could do that same move and still have 4 decent big men in our rotation.
This trade isn't a blockbuster by any means, and in some respects it's a little disappointing as a fan, but I genuinely think it will greatly improve our team and was a move that we will come to value.