I think that qualifies as "interest". If you weren't interested, would you bother to spectate and analyze?
I've heard of L4D. I'm sure that I have friends who play it. But since I'm typically not interested in FPS-style games, I don't talk to them about it. As such, I haven't been exposed to the terminology. I hear "Boomer" and, like others here, think of the BSG character. Or an SSBN. If I ever run the FP in question, my first thought when I run into said mobs will likely be "infected terrans" (from the original SC) or "sappers" (from WC2). "Boomers" will just confuse me.
In TOR news, I have now run a hard mode. BT was really easy, other than the final boss one-shotting people (was quite a change after farming social points in the normal mode). I learned a couple things, though: 1) Even when slowed, you move faster running forward/strafing than backpedaling (learned from the BH's example). 2) If you're facing her, running forward (ie, through her) will not get you quite far enough to be clear of the nova. Fortunately, she was low enough, and I'd done well enough keeping hots up on everyone, that the group was able to finish her after I got clubbed like a baby seal. But for most of the run, I felt like I was barely doing anything. Was way easier than scrambling to keep Scorpio alive while I solo yet another champion-rank mob only to have it drop +str gear (the attribute that not a single one of my companions uses).
I also finally took the plunge and bought one of the fancy level 50 vehicles (the one from the VIP vendor, since it matched my ship the best). And I picked up a hat from Nar Shadaa that looks good with the Imperial Pilot set, which will cut a couple days off my fleet commendation farming.