1. A computer readable medium including program code for providing a message-based interface for exchanging opportunity data, the medium comprising: program code for receiving via a message-based interface exposing at least one service as defined in a service registry and from a heterogeneous application executing in an environment of computer systems providing message-based services, a first message for requesting replication of opportunity data, including business transaction information and identification of parties involved in a prospective business transaction, the first message including a message package hierarchically organized as: an opportunity replication request message entity; and an opportunity package including an opportunity entity, wherein the opportunity entity includes an identifier, a processing type code and a process status valid since date; and wherein the opportunity entity includes a status entity from a status package; and program code for sending a second message to the heterogeneous application responsive to the first message.