It's not the editing software that makes a video look good, it's HOW you use the one you already have. Well, in this case Windows Movie Maker can't beat Sony Vegas or Final Cut Pro, but that's not the point.
Too many times people have said "Ooooh that video looks awesome! What software did you use?" and they get the reply of Sony Vegas, which turns out to be the same one they use. T11 probably use Final Cut Pro since they use MACS (correct me if I'm wrong).
Think about it like this: You have a normal deck of Tally's that you flourish with but you aren't that good. Then you see a video of The Virts using Normal bikes, you're probably not going to change from Tallies to Bikes just because they can do things that make your eyes bleed (metaphorically speaking, my eyes have never bled before....right) doesn't mean the Bikes are better, it's what they do WITH WHAT THEY HAVE is what makes something look awesome.
Now, I'll admit that I'm not very good with cards since all I do are DnD and Madison's some simple magic effects with Bikes or currently a Black Tiger deck. I've someone in the "Just Flourish" video do amazing things with Jerry's but I don't want one, I'll use what I have to do great looking stuff.
So pretty much what I'm saying is, get REALLY good with what you have then you'll find out that you can make spectacular video's with the crappiest software even though the person next door has the most professional software.
Remember, these people are professional's who have probably studied film making or in the case of Dana, studied composing music and has spent hours learning how to use the software so he knows the insides of the software like the back of his hand.
Well that's more than 2 cents but anyway, I hope I helped =D