Be careful -- they're rapidly going obsolete. No one wants to fab old EPROM processes, and no one wants to package PLCCs anymore. If it's neither of those, I think you've got a bit more time.
There are "compatibles" out there, and some of them are very good indeed, but they're not without their hassles.
One-off hobbiest/repairman/desperation quantities will be available for years. It's industrial, new-build quantities that are going to be problems.
And, yes, the 68HC11 was on December's EOL list, so I hope anyone who was using it in products has a plan! (Or hire my company, we fix things like that... not that it's the most fun work in the world, we have other things we'd rather be doing....)
