Ubuntu revealed the codename of Ubuntu 18.04 its called Bionic Beaver.
The big change is that Ubuntu has drop Unity and with 18.04 comes the desktop GNOME 3.28.
The final LTS version comes at 26th April: Stable Ubuntu 18.04 LTS release
Ubuntu 18.04 daily builds are available for download now.
But before you do that, let me tell you that it is in very unstable phase and you’ll encounter a number of issues so don’t use it on your production system or on your regular computer.