Here is the release overview presentation with screenshots highlighting the important features and functionalities introduced in Salesforce Spring 15

For videos, release notes and other resources on Spring 15, please navigate to URL http://www.salesforce.com/customer-resources/releases/spring15/

And here is the list of past release overview decks

  1. Salesforce Winter 15 Release Overview with Screenshots
  2. Salesforce Summer 14 Release Overview with Screeshots
  3. Salesforce Spring 14 Release Overview with Screenshots