Wow! as outstandingly positive user experience has often been cited as an important design target in industrial product development contexts. Wow is assumed to be more than acceptable user experience, it is something that exceeds users' expectations. There is relatively little research on the specific concept of Wow and how it can be achieved. In our multi-year Cloud software project with over 20 industrial partners we have found a strong interest in establishing basic understanding of this concept and further, design implications for bringing Wow to Cloud services. To this end, we first conducted two small online surveys to understand the general user perceptions of Wow. We then explored two specific Cloud application domains -- personal contact management and information security services -- in more detail by conducting two rounds of user interviews on how Wow is perceived in these domains. In this paper we present the results of these user studies and draw design implications for Wow in Cloud services. The main design implications include providing positive surprises to the users by pushing dynamic service features through the Cloud, supporting automated data integration of and universal access to user's personal data, and moderating the level and types of Wow for "serious" application domains.