A guy runs past me, and while he does so I hit the ground with a Gravity Hammer. He gets behind me and starts an Assassination, and halfway through the animation it registers that I had hit him and he dies. I then got a Showstopper award.

I should've saved the clip but I'm not used to being able to do that, having only recently gotten a 360 with a Hard Drive. I haven't really done anything with the File Share.

So, there are two things you can do.
1) You can select a portion (or entirety) of a clip for a "highlight" and Twitch will save it on your channel.
2) You can export clips to YouTube straight from Twitch.
If you don't do either of those, I think the clips stay around ~ 2 weeks before Twitch clears them out.

Ah, looks like Twitch no longer automatically archives broadcasts, so I had to enable that feature in my Settings. I'll play around with it and see how it works. I think the ideal use case is to let the XONE/PS4 stream to Twitch while I record high-quality 1080p local capture for later editing on the Game Capture HD. The only tradeoff there is that the Twitch stream quality isn't nearly as good as what I generated for Halo 4 last night. :-\

Do you have to actively mark them as highlights?

Yeah, after the stream is done, you go to the clip while logged in, and hit the 'options' (*) button next to share and from there you have the option to choose Upload or Highlight.

I have my youtube gaming channel linked.

If you want to make a highlight, it takes you to another screen where you have in/out sliders so you can choose the region you want.

Hope it helps! Hope to see a bunch of Destiny highlights in the next few months. :)

I don't have a capture card so I only stream Skyrim and Mass Effect 3 when I play on PC.

1) You can select a portion (or entirety) of a clip for a "highlight" and Twitch will save it on your channel.

2) You can export clips to YouTube straight from Twitch.

If you don't do either of those, I think the clips stay around ~ 2 weeks before Twitch clears them out.

Thanks for coming! Hopefully next week won't be so lagtastic.

Lagtastic? I have no idea what you're talking about…

I'm unfamiliar with Twitch, was that recorded in any way or can one only see it live? Just curious.

I'm fairly new to Twitch as well, I've only streamed some Titanfall from my XONE before this. I believe there's a way to have Twitch record a stream for later viewing, but I'm not sure how that works. I did record a local copy, though, just in case anything crazy happened. :)

I'm curious to know how the streaming quality holds up for the night…