I am eager to pursue SAP HANA certification because it's new SAP technology that will evolve in all SAP platforms in near future.
I have almost 4 years of ABAP development experience. Is it absolutely essential to have BW BI experience for good growth with HANA?
Well, few days back I'd have said that it would help. But now HANA has increased the breadth so wide and far that covers many aspects of SAP world including ABAP, SAP business suite along with BW and data warehousing.
So you can very well continue to focus on your ABAP skillset and realign it to HANA. Please refer to ABAP for HANA community as mentioned below.
Currently there is no certification for ABAP for HANA, but I am sure it will come soon.
without commenting the necessity of learning HANA etc. I want to point your view on something else very important. To be successful in a HANA certification process you have to be very strong in BO Tools. It makes absolutly no sence, I know, and it is no big win in the full usage of BW and HANA or just HANA, but as SAP wants to sell their tools a big part of HANA course and certification is based on BO knowledge.
So, if you are a good BI guy and strong developer and very fast learning HANA beginner this will be not enough to succeed the stupid certification questions concerning BO frontend toolset.