You can apparently link quests and spells in select channels now. This doesn't work in General or custom channels(without a mod of some sort) but it does work in party chat, raid chat, tells, the Trade channel, guild chat, and things like that. Basically, if you can link items in the channel, you can now link spells and quests.
The quest link is pretty neat, it gives a brief description of the quest you're linking and a list of its requirements. The color of the text also reflects what level the quest is. Grey quests will have grey links, red quests will have red links. Shiny!
The spell links are pretty simple, not much to them. Light blue links, and simply includes the spell's tooltip. Not as useful as quest links, but that doesn't mean it isn't shiny!