Depending on how open they are with their UI modding (which it looks like they are going to be very open with it) I can see people making new versions of it within the first few weeks. I'd prefer just a circle on the ground around my target that I'm aiming at.
But, I understand what the purpose of it though. It's there to let you know which mob you are targeting and trying to hit. Watching the video it looks like they aren't doing unit frames in this game, so it would be very hard to determine who you are trying to hit if you can't see some type of indicator. Yes, the glow is a bit over-the-top, but I see why they have it and I expect that someone will make a mod within the first few weeks to make alternatives to it.