Information on streaming live video...

Hi, Quite new here, quite a newbie, and completely ignorant to what I'm asking.

So, I'm looking information about streaming live video to multiple users (let's say 1000 users).

Example: I'm hosting a show in a part of the world (any part, that has normal Internet access, for the shake of the example). I have 3 cameramen who are recording the show. The signal from the 3 cameras goes to a single computer, where a director is 'mixing' and 'directing' real time. The end result gets into a server and 'anyone' from 'anywhere' can be in a specific link (my website for example) to watch a video at almost real time.

Does this make any sense really?

I know *for a fact* (which may be stupid after all, since I have nothing to do with video or streaming or the internet pretty much) that I can get 3 people to have the cameras and a director. I realise that the end video will need to be 'downsampled' (brought to lesser quality) for broad/multicasting on the Internet. What I'm hazy about is the upload/download part of the idea. Do I need a dedicated server? Will a multicast option save tons of bandwith, or not? Do I need more than 1 mbit upload connection?

For the above questions let's assume that the length of the show will be around 2 hours, around 1000 people will watch and the quality of the video will be 'poor' (so no HQ things, unless it's really easy to do).

Any links, programs, ideas, support, comments are most welcome, please.

Thank you,

Nikolas