Is it possible to developing SP solutions based on SharePoint 2013 Preview. I Get SharePoint is not installed when running Visual Studio 2012
It is possible as SharePoint 2013 Preview is just an earlier version of SharePoint but still deploy and register itself nearly like the RTM bits (at least for VS recognition, there is no changes).
Make sure that your installation of SharePoint is working as expected. You must be able to connect to the central administration and the relevant services must be running.
Make sure that you add the office tools to your VS2012 setup : http://msdn.microsoft.com/en-US/office/apps
Make sure that the registry key indicating the SP2013 is installed is present
Anyway, you should grab some RTM binaries, if you need to do anything serious, that's pointless to suffer for the CTP issues since the final bits are available (unless you don't have access to an MSDN account of course).