I agree 100% this allows the wrestler to really work on what they have to say. Because it isn't live. Nor is it in front of 10,000+ people. Some of the best promos in recent memory I have heard, were off the titantron. You remember when they teased us with The Rock about a year ago through the titantron? That was great.
Basically the best part about a video promo is, there can be retakes. The professionals of the business can show you some pointers in how to really get the croud eating out of the palm of your hand. Some people aren't naturals and I do believe this will really make things work a lot better. When making a speach, no matter how much you practice and think you know what you're going to say. Sometimes, you get tounge tied, and have to improvise. When in front of a live croud like the wrestlers do, I can see the trouble that a superstar may have in the making of a promo. Video Promos, take that kind of thing out, they allow the promo to be more fluent, while stating possibly the exact same thing they want you to see out in the live croud. With no mistakes.
Another great thing about the video promos is the fact that it can promote a superstar's finisher to be more dominant. Remember when Brock debuted? Paul-e had video promos coming out the arse on him. He is easily the most over superstar in such a short amount of time that I have ever seen. It made the F-5 look 10x as dominating as it actually was. Say they wanted to promote a superstar's normally weak looking finisher, and make it look way stronger. Using a video promo would do just the thing. Like, Koslov, if it were me. I'd have a video promo of him just headbutting weak walls to crack them down. That way they can say "OMFG His head cracks walls, just think of what thats doing to that mans ribs!"
As allready mentioned, it can also promote an up and coming superstar. While, I don't really like this because it can seriously fall badly if the Superstar drops the ball. I.e The Highlanders. But when they show up, and live up to expectations it shoots a superstar's career way faster than a superstar trying to get over on his own. I.e Kofi Kingston. I remember when he debuted on RAW. I was very excited and ready to see some huge things out of thise young superstar. Simply because of all the titantron promos, videos, etc they were doing for him to put him so much more over than he would have normally been. So in conclution yes, Titantron promos. FTW!