We've released an update to the SteamPipe beta. It is now compatible with the regular game.
Now everybody can play together and admire each other's headgear. Both SteamPipe and non-SteamPipe clients can connect to SteamPipe and non-SteamPipe servers.
We are planning to convert all clients to SteamPipe next Tuesday. If you opt in to the beta before then, you will be one step ahead of everybody else. You'll be able to take advantage of the faster boot and load times. If you are experiencing the bug where Steam wants to validate your files every time the game boots, opting in to the beta should make that problem go away.
Although we don't expect that anyone will have an urgent need to opt back out, I would like to point out that if you do need to opt out, the process is very painful. You will need to redownload the entire game, and also move any custom files back to the original installation folder.
The FAQ has a lot more info.
https://support.steampowered.com/kb_article.php?ref=7388-QPFN-2491
Any more questions? Post them here.