So the patcher's server was changed recently and the current patcher can't connect to it to update itself with the new address which means that everyone will have to download the new patcher manually and then put it in your AoE3 directory.
If you run the current patcher you will probably get this: Error grabbing master server list.
The error might not show up for everyone as I have been told but in case it does here's the fix...
DOWNLOAD NEWER VERSION FROM HERE!
The deal is the same, run it as administrator!
It will be included in the version 5.5 installer so after that everything will be automated.
We will probably do more changes to the patcher and its server so I'll update this post with news as they happen.
Thanks for playing!