Just as a followup to this. The process that I am using to do the upgrade is as follows:
1. Install Postgres 9.3 in /opt dir.
2. In 9.0 instance update spclocation in pg_tablespace.
3. Update the symlinks in the pg_tblspace folder.
4. Move the tablespace folders to new location.
5. Run pg_upgrade.
6. Test upgrade results on 9.3 cluster.
7. Run the sh files created by pg_upgrade.
8. Uninstall Postgres 9.3 in /opt dir.
9. Install Postgres 9.3 in default location.
10. Enjoy Postgres 9.3.
I could actually move the 9.0 cluster after moving the table spaces and install 9.3 in the default location as the documentation shows. But I haven't experimented with that scenario yet.
-Joseph