SAP BI pushing data into SAP PI

Hi All,

What is the best method to push data from SAP BI 7.0 into SAP PI 7.3. I wanted to know what is SAP's recommendation on moving data from SAP BI to SAP PI ?

I see we can use ABAP Proxy/ RFC to push data from SAP BI to SAP PI. We are planning to move from SAP PI 7.3 to SAP PI 7.31 single java stack with SAP PO, in some SDN articles it mentions that " ccBPM and ABAP proxy needs to re-create from scratch in PI 7.31". Can't the ABAP Proxy code be migrated to SAP PI 7.31, what are the constraints behind this.

http://wiki.sdn.sap.com/wiki/display/XI/Features+of+PI+7.31

Thanks in advance

Ravijeet