Can anybody give me an example script on how to use this new chat api?

Requiring chatservice

So the first step to using the epic feature of the magic chat service, you need to do a thing called require.

I'm assuming you know what is require, if not: http://wiki.roblox.com/index.php?title=Global_namespace/Functions_specific_to_ROBLOX#require

So the chatservice is not a service (haha), and it is deeply hidden in the game.

local chat = require(game.ServerScriptService.ChatServiceRunner.ChatService)

AddSpeaker and GetSpeaker

These both functions are great!

So, AddSpeaker just adds a fake player onto the chat which can chat!

Here's an example:

local chat = require(game.ServerScriptService.ChatServiceRunner.ChatService)
local speaker = chat:AddSpeaker("Bob") -- adds bob
speaker:JoinChannel("All") -- this will be required otherwise he wont be allowed to chat in the channel "All"
speaker:SayMessage("Hey, my name is Bob!", "All") -- the "All" just makes it chat to the channel where everyone is!

Trying to add an existing speaker will result in an error. So here comes: GetSpeaker! It just tries to find a real player which can speak or a fake player in the chat.

Usage: chat:GetSpeaker("Speaker Name")

Once we get a speaker, we can change his Font, ChatColor and others!

Fonts, ChatColor, NameColor, etc.

This is the fun part. Not only you can make your text almost unreadable, but you can fake John Doe and make his chat pink!

The full list is: Font, NameColor, ChatColor, TextSize

Remember, always set those properties with SetExtraData

So, let's get John Doe and do some silly stuff to him!

local chat = require(game.ServerScriptService.ChatServiceRunner.ChatService)
local speaker = chat:GetSpeaker("John Doe") -- gets john doe
-- note, i did not add him to the channel ALL
speaker:SetExtraData('Font', "Arcade")
speaker:SetExtraData('NameColor', Color3.fromRGB(255, 255, 255))
speaker:SetExtraData('ChatColor', Color3.fromRGB(255,105,180)) 
speaker:SetExtraData('TextSize', 70)