At the moment, there aren't many uses for ThunderBolt/Light Peak. It's still a new tech and it's in the middle of being rolled out.So, what are you doing with Thunderbolt?
High res monitors and external hard drives seem to be the most commonly used pieces of hardware at the moment. I imagine 4k/"retina" monitors, which will be coming soon, will require a ThunderBolt connection.
ThunderBolt also has the potential to accommodate external GPUs. That's pretty huge, imo.
http://www.tomshardware.com/reviews/...bolt,3263.html
So yeah, at the moment, it's not a "must have" feature, but it's going to become increasingly more important over the next few years.