Just a few minutes back I read this link…About gartner sayings on PI future..
With NetWeaver PI’s future unclear, don’t use it for strategic projects, Gartner says

…..And so many links debating on the same in abundance is only increasing the risk of confusion…..

In fact I am recently studying on PI with a aim of replication of a targetted table underlying SAP to a non-SAP database. I always liked the concepts of snapshots in Oracle which does not hold true when you have purchased Oracle bundled with SAP. In fact till for me, introducing PI is nothing but introduction of two more sets of RFCs to manage and paying for the trraffic flow even in owned network.

SAP should look somekinda analogus feature and opportunity, may be through a web service instead of forcing customer to invest into one more product in a separate hardware box…..