I am not sure, that ADO is a replacement.
It is an other layer of API, it encapsulates OLE DB using components.
Oracle is very good RDBMS, but licencing it would cost a small fortune and requires good DBAs.
You're quite right. Sorry about that.
I was confusing ADODB with ODBC apparently, which are totally different layers like you say: http://en.wikipedia.org/wiki/OLEDB