We do not do ETAs but since its already in unstable, it will be available next sync.
For future reference we do not use the .0 of mesa, which to quote mesa themselves:
Mesa 26.0.0 is a new development release. People who are concerned with stability and reliability should stick with a previous release or wait for Mesa 26.0.1.
No sane distro uses the .0
26.0.1 came out on Wednesday 25th Feb and I wanted more then couple days testing before sync.