What would you call the dot-dot-dot in this sentence:
The weather is nice today, so…
Would you call that an ellipsis? Or is an ellipsis only in the middle of a sentence, as in:
The film is absolutely…amazing.
(Actually, this is a punctuation question, not a grammar question.)
Yes, an ellipsis can occur at the end of a sentence.
That is an ellipsis, in both cases. It indicates that words were dropped; the position within the sentence doesn’t matter.
By the way, some would argue that your first example needs a fourth dot, as a period to end the sentence.
Just like if it was a question, you would have the question mark and 3 dots for the ellipsis:
But this may get into a big argument among grammarians, between the ‘traditionalists’ and the ‘logicians’. It seems to be a big issue right now; possibly because this ‘rule’ is in the process of changing.
Don’t you mean punctuatiarians? 
Thanks for the quick answers!
I’d have to ask for a cite on both of these.
The fourth dot is only used when a fragmented quote lifted from a paragraph includes a full sentence. So the four dots indicate [period] sentence has ended [ellipsis] material has been removed {quote continues}.
And I can’t think of any style that would accept a question mark followed by an ellipsis as a properly punctuated single sentence.
Are you saying it is the ‘traditionalists’ or the ‘logicians’ who accept these, and where would you find these people?