Ravi,
I looked into both Informatica/OBIEE and SAP HANA/BO (Got trained for both). If you look for future HANA and BO (If not BO, some other reporting tool can be used) is going to be good. Since we are going to model within HANA and all the data which we are going to pull out of HANA is going to real time, I believe most of the SAP customers will prefer that.
I felt that OBIEE is not that much user friendly. OBIEE depends on the cache which needs to be explicitly refreshed. Instead when you are trying to run reports from BO, it pulls directly from HANA.
I am also in the same boat as you. I preferred to move to SAP HANA. You can decide your self. I believe oracle is slow when compared to SAP when it comes to IN-MEMORY computing. SAP realized the power of IN-MEMORY computing probably around 4-5 years back. Oracle is coming up with EXADATA servers which are much faster.
Let me know if you need more info.
Thanks
Sree