This is what i heard from my friend
there were 4 endings the writer couldnt decide since he is gone alreadi...
so... the endings were...
1st from... http://www.kejut.com/doraemon1
2nd.. Nobita wus acualy a man in a coma dreaming
about Doreamon and his friends. his wife is acauly giants's sister
and um i cant remember his friends were something else in that life
3rd... Well in this ending... nobita got hit by car... he in coma.. so to save him..
doreamon sold all his tools and blah blah to save nobita but eventualy dies.
4th.... It wus all just a stupid dream...
Well i hate the 3rd and 2nd ending the most the 4th one i not sure it wus 1 of the endings... but i still prefer the 1st ending...

DORAEMON YOU ROCK DON'T LEAVE ME.