This looks like a very cool idea. From the devs:
In patch 4.1 we’ll be introducing the Guild Finder, a new system designed to enable easier and faster guild recruitment. Guild leaders and players who are looking for a guild to call home will use the Guild Finder to meet one another and begin communications that can lead to a prosperous membership.
The Guild Finder is intended to act as an in-game bulletin board for guilds that are actively recruiting. Previously in World of Warcraft, your options were limited. You would have to publicly post on your realm forum message board, or speak to other players directly via private messages or the chat channels. That can be a time consuming process. Guild Finder will allow your “looking for new members” message to work 24 hours a day, accessible to all of the characters in your faction, from anywhere in the game.
This will reduce trade chat spam to some extent, depending on how widely known it becomes and if people decide that it’s a pretty cool tool. I think it looks great and will be a big help to getting people into the right guilds.
I didn’t see anything on that page about creating guilds, but that’s easy enough. Offer 10 or 20g to anyone who signs, become official, then fill out your info in the widget.
Will it do away with blind invites? I don’t think so, but I think they may become fewer.
Will it help or hurt smaller guilds? I have no idea, but I can think of arguments either way.