By now you might have seen on blogs and documentation that there are new datatypes introduced in  SQL Server 2008, they are:
 

DATE - ANSI-compliant date data type
TIME - ANSI-compliant time data type with variable precision
DATETIMEOFFSET - timezone aware/preserved datetime
DATETIME2 - like DATETIME, but with variable precision and large date range

GEOMETRY - "flat earth" spatial data type
GEOGRAPHY - "round earth" spatial data type
HIERARCHYID - represents hierarchies using path enumeration model

From the first look the first 4 types are not 'new' faces in SQL Server, as you have DATETIME & SMALLDATETIME datatypes etc. The other 2 datetime datatypes are getting introduced with SQL 2008 version. Then coming to rest 3 data-types are very new to handle GEO-metric type of data and they are considered as .NET system UDTs.

Moreover if you are working with June 2007 CTP for SQL 2008 then you wouldn't be able to see these new data-types, they will be available in future CTPs of SQL Server 2008.