This talk is actually about porting to the Weston reference implementation, e.g. all GL hacks are Weston-specific.
Tizen is currently the only system that uses pure Wayland. There are also a few set-top boxes that are based on Wayland. Most of the toolkits OTOH do support Wayland. However, many extensions and applications have X11 or GLX specific things. Currently Weston only supports EGL/GLES and not GLX, so the GLX-specific things will not work.
Manuel has created a wrapper library that pretends to be GLX 1.2 – a low version to avoid needing to port extensions, and anyway most applications have fallbacks.
Example: porting of the OpenCPN application. It uses wxWidgets (which already supports wayland through its GTK+ backend). However it also uses GLX. Even with the wrapper, some porting is needed for the extensions that are used.
Remaining problem: wayland doesn’t have the concept of minimising a window, so that’s not possible. Same with absolute screen positions.