Yes and no.  In SQL 2005, a user can own multiple schemata.  In Oracle, a user can only own one schema.

For example, in SQL 2005, user "x" can own schema "y" and schema "z."  So it can own two tables called "mytable" which could be referenced as follows: select * from y.mytable; select * from z.mytable.  As BOL states "Beginning in SQL Server 2005, users and schemas are separate, and schemas serve as containers of objects." 

So really a schema is just another object owned by a user, which serves as a container for other objects.  In Oracle, the user and schema owner are one in the same.