The UK has a scheme now that allows orphan works to still be used.
Copyright Orphan Works
You can apply for a non-exclusive license to use an orphan work. You have to pay an application fee, a license fee and demonstrate you've made a "diligent search" for the copyright owner. The license lasts for 7 years and is limited to the UK. Any license fees generated are held for up to 8 years and if the rights owner comes forward the fees are handed over and no new licenses will be granted.
Seems like a good idea. Not sure how well it works in practice. I took a quick look at the register and there weren't many works on it.