SAP billed its launch EVENT of BI4as game changing for BI as a whole. I would doubt if BI4 by itself changes much but this somewhat obscured the real message that HANA is designed to change the game and not really from BI side of changes.

Some of the commentators on the web have noted that SAP probably would not enthusiastically support MDX. This would mean for vendors who pull data from SAP BW using MDX, there is going to be some significant issues interfacing with SAP BW.  However,  others have noted a work around to this issue, which is to either pull the data from the staging area from SAP BW or pull it from the source. 

However I think the most game changing part of the announcements were around SAP HANA. This conclusion is based on the assumption that SAP could actually do what they said they would.  What has been indicated at the launch event is that SAP may actually put the backend (OLTP source systems) onto SAP HANA. Some of us who have worked with SAP for what seems like ages, also wonder why SAP has not adopted new technologies for its backend. This has the potential, depending on both customer adaptibility and how much data-model itself is changed by SAP, to disrupt the BI competitions gameplan completely.

I think SAP will face big resistence from the existing customers to change the data model of backend systems. From transaction point of view, auditability and persistence is harder to guarentee with electronics technology such as memory; to a more time tested mechanical devise such as a hard drive. However with a good roadmap, SAP can migrate its customers into new technology.