Make sure that when you installed SQL Server Denali CTP3 (I am assuming that you installed this as a default instance on your local machine since your workspace is targeting the localhost), that you installed Analysis Services in the Tabular mode. In Denali, there are now two modes that Analysis Services can be installed in - the traditional Multidimensional mode or Tabular mode. If you wish to have both of these modes available, you will have to install separate instances of Analysis Services - one for each of the two modes. To create an Analysis Services Tabular project, you will have to target an instance that has Denali Analysis Services installed in Tabular mode.
There is a good article on how to set this up here: http://blogs.msdn.com/b/analysisservices/archive/2011/07/13/welcome-to-tabular-projects.aspx