It reminds me Shakespeare's quote... "There is nothing good or bad in this world..." 
Linganathan...
Hope you have gone through this... http://www.saphana.com/community/learn
HANA development is definitely good choice if you are interested in Data Base Technologies and developing/implementing things at database level.
ABAP for HANA is other area where things are not yet stabilized and I think we should wait till HANA DB plays primary role (at least at customer projects). I don't think HANA training is required to gain knowledge in this area as you can get it on SCN.
Lastly, in my opinion, If you want to play key role in your projects as HANA developer then I don't think you will get enough time to improve or expertise your ABAP skills.
Regards,
Naveen.I