Update: The service has now gone live in most countries. Pricing is 7.99GBP a month in the UK and 7.99 Euro a month elsewhere if you sign up before September 15th, along with the free 30 day trial. The price will increase if you sign up after that date (probably to 9.99 GBP / Euro a month). Thanks for confirmation, everyone!
Google has updated its international availability page for the Play Store, and the All Access section has had a slew of countries added - all European. Austria, Belgium, France, Ireland, Italy, Luxembourg, Portugal, Spain, and the UK will be the first EU countries to get a taste of Play Music All Access, Google's all-you-can-listen Spotify competitor. Pricing for the respective markets is not yet known.
That brings All Access to a total of 12 countries, only one fewer than the entire Google Play Music service supports (Germany is still missing from All Access).
The expansion of All Access remains otherwise unannounced at this point, as far as we can tell, but an update to this page should mean users in these countries will start seeing the service become available in the coming days. However, it's also possible someone jumped the gun, so don't panic if you're not seeing it by then.
That said, if you are in one of the newly-supported countries, let us know if you can now sign up for All Access! We've also reached out to Google for confirmation.