How does Postgres 9.2's streaming replication handle schema changes, and initial table setup?
If you intend to use PostgreSQL's built-in streaming replication, then you seed the replica with a base backup - a file-system level copy of the original database. So it already has all the tables and data from the master. pg_basebackup is usually used for this.

Streaming replication reads changes at the block level from the write-ahead logs, so the databases are kept physically the same. Since DDL is, just like DML, recorded in the WAL, DDL and DML are both transparently replicated.

See the documentation on HA and replication in PostgreSQL for more information.