At least from version 3.3.0, the RENAME TABLE statement has been almost fully implemented, to only thing missing is connecting the rename function, to the statement. I have know idea why this hasn't been done a long time ago.
I've created a forum post, trying to answer this question, it can be found here.
The patch enables you to give ICE the following statement:
RENAME TABLE oldName TO newNameThe attached patch are tested in version 3.3.1, but should also work in 3.3.0, and should be applied in the root ICE source directory.
renameTable331.patch (1 KB)
If you issue the RENAME TABLE command in the current implementation, the table file structure are corrupted. Therefore do not try to rename a Infobright table without applying this patch. I've create a bug report here.
I got a response to the forum post I created. The answer to why it wasn't implemented was that renaming tables in ICE aren't officially supported, and therefore this wasn't a bug. See the answer here.