The new versions of Lightning will be released on May 1st for both Sales and Service Cloud. Although these new version will be available starting May 1st, there are a number of features that will not be available on the release date. Release dates for specific functionality depend on the Salesforce instance and the new release date for that instance.
Please note that existing customers of Sales Cloud and Service Cloud will automatically receive the functionality of the new Lightning Editions, so there will be no need to upgrade or change editions at this time in order to receive the benefits.
Here are the prices and feature releases for both Salesforce and Service Cloud according to the Salesforce Blog:
If you would like to know the dates in which this new functionality will be available for your current instance, please go to the Salesforce Maintenance Calendar and you can check the functionality release dates. Shortly, we will post a list of all the release dates and functionality that comes with the specific edition.
If you have any general questions regarding the Lightning Experience or if you are ready to get your team on-boarded and need some guidance working with the new functionality, please reach out to us at firstname.lastname@example.org. We would be glad to help!