I think that John Head's take on the IBM/SAP "Atlantic" announcement at Lotusphere has pretty much hit the nail on the head. IBM was already doing SAP integration on their own, but SAP's endorsement was a major missing factor. The joint project, and the appearance of SAP's CTO on stage at Lotusphere to announce it, remove a major leverage point from Microsoft in SAP shops.
Of course, corporate alliances are notoriously fleeting. I therefore suggest that the thing to look for next year is continued formal presence of SAP at Lotusphere. I.e., look for SAP to be sponsor at Lotusphere 2009. It does not necessarily have to be at the top "Knowledge" level to prove that the alliance is still going strong, but I would think that demonstrating an ongoing commitment to Atlantic would merit a "Solution" or "Vision" sponsorship.