Streaming live to co-hosts I've recently started livestreaming, and during the test stream feedback was received that I tended to concentrate a fair amount on the game I was streaming, and not able to respond to commenters on the stream, despite my moderators' having a system to flag posts for my attention.

To resolve this, I started a Skype call with said moderators so they could participate in the stream too. However it was quickly noticed that their participation was limited to responding to comments and talking about the site that the stream was being hosted on (it's a YouTube stream embedded in my game site), because the stream output lags by about a minute.

To fix that, I started sharing my screen on Skype, thus allowing the moderators on call to see my screen and therefore the stream with much less delay. However, this started causing problems because it made the video stream lag for the viewers, and I had to stop the Skype video.

I'm using XSplit Broadcaster, and during real streams I will be streaming to YouTube as well as to a local recording. XSplit is perfectly capable of broadcasting to multiple sources (and my bandwidth easily allows it - I get a minimum of 16Mbit upload and the stream quality I'm sending is 4.5Mbit), however I'm wondering if there's any way I can provide a live stream to my moderators, so they can see what I'm seeing and participate properly in real(-ish)time.

Any advice on this would be much appreciated!
You need your own stream server.  The problem with services like YouTube and Twitch.TV is that your stream has to go through a lot of processing and content distribution on their end before it goes out to viewers.  That processing takes time and results in lag.  You can send the exact same stream to your own stream server and have it directly related with far FAR less delay (sub-second to a couple seconds), but are limited to the capabilities of your stream server to meet demand.

I've only done this kind of thing with Windows Expression Encoder in the past using a Windows Media Streaming server which is pretty easy to use, but only works on WMV files and thus isn't really all that good of a modern solution for h.264 video in cross platform streams.  RED5 should theoretically be capable of relaying a stream for you and you could either set it up locally or preferably throw it up on a VPS somewhere that can do the relaying for you (as 16mbit will get consumed really fast sending a 4.5mbps stream to multiple people).

Streaming is unfortunately not particularly easy to get setup and going for yourself though and that is a big part of why services that simplify it, like Youtube and Twitch.TV, are so popular despite their massive lag times.