Oh no.... ****. I am just coming from Nokia care. The guy there take my 610 and updated assuming it too has got 7.8 update but after that it turned out old update overright only. And I loose all my apps and everything.
but I saw 7.8 on his 710 and he said he updated 510,710, and 800.
So final news is, update is out for all lumias except 610 in INDIA!!! And I hv 610. Unlucky me :-S