The libwayland-server and libwayland-client components that are used to provide an API to the Wayland protocol will now be under the LGPLv2 rather than the MIT code license. The libwayland-client is used by the tool-kit libraries such as Qt, GTK+, Clutter, and any other application wanting to tap Wayland directly. The libwayland-server is used by any Wayland compositor.
Kristian is also going to change Wayland's demo compositor and the sample Wayland clients from being GPLv2 to now be LGPLv2 as well.
This announcement was made on the Wayland mailing list.