New with MirAL 1.3 is support for workspaces, which is part of their effort to support workspaces for the Unity 8 desktop with Mir. MirAL doesn't offer any transitions/spreads but rather just rather basic workspace switching for now. Keyboard shortcuts make the workspace switching easy.
MirAL 1.3 also adds support for "previous window in application", miral-shell now adds a background (their default background just shows off available keyboard shortcuts), and there are also various bug fixes to this Mir abstraction layer.
More details on this weekend release of MirAL 1.3 via Alan's blog.