While you will have some SSRS reports that can be replaced with Power View reports, be aware of its limitations that can prevent the replacement of other reports. The limitations are as follows:
Power View does not have nearly as many customization options as SSRS. With SSRS, you can change just about every property of a report item, but Power View is very limited in terms of the properties you can change.
The current implementation of Power View requires the installation of a Silverlight browser plugin. This can add complications that you generally don't have with SSRS because it does not require any browser plugins. In addition, Silverlight is a dying technology and is being replaced with HTML 5 (Microsoft is working on a HTML 5 Power View client).
Power View in SharePoint requires SharePoint Enterprise and the installation of Reporting Services in SharePoint Integrated mode. SSRS will work with the Standard edition of SharePoint and has a Native mode that does not require SharePoint. Power View also works with Excel 2013 (ProPlus edition only), but many companies have not yet upgraded to it and are still using Excel 2010. Additionally, if you are using Excel 2013, it is likely that you still want to use SharePoint Enterprise to share the reports instead of sharing the workbook.
Power View does not support the passing of parameters, whereas SSRS does.
Power View does not have any means of scheduling reports or automatic report delivery. On the other hand, SSRS has a sophisticated way of scheduling and delivering reports using subscriptions.
Power View does not support custom code, so there is no way to extend its features. SSRS is very flexible in allowing you to extend its code, so you can do just about anything with it.