Oh HLS! a little ahead of it's time
We have been looking for a live streaming solution for our clients and have looked at many options.
The best way to do this we have found was going straight to a Wowza Service using Adobe Flash Media Encoder at 800 Kbps and 1200 kbps for standard def Live.
Video
Format: H.264
Profile: Main
Level: 4.0
Keyframe Frequency: 10 seconds
Frame Rate: 24 fps
Input Size: (any)
Bit Rate (any; at least 800Kbps recommended)
Audio
Format: AAC
Channels: Stereo
Sample Rate: 44100Hz
Bit Rate: (any)
However we did not want to set up a Wowza ourselves and looked for a turnkey solution.
The guys at
http://www.rokuchanneldevelopment.com/ have made it very easy and created a Custom Middleware application that allows you to manage you live stream and VOD on the Roku easily.
If your looking for a fast managed and affordable soultion...check them out for you HLS and VOD Roku middleware solutions!

