| | Re: "What will tomorrow be?"
What will tomorrow be ? is correct in terms of the word order. Think of the answer :
Tomorrow will be quite a difficult day.
This shows that tomorrow is the subject of the sentence, and Wh- question word order in this type of question, where the answer focuses on the object or complement, is always :
1. Wh- word : What, where, when etc
2. Auxiliary verb : can, will, do etc
4. Main verb
5. Anything else
So that gives all the following :
Where (1) - do (2) - you (3) - live (4)?
When (1) - can (2)- we (3)- see (4)- you to talk about it (5)?
What (1)- will (2)- tomorrow (3) - be?
The odd thing about this sentence is the verb form itself. Will + infinitive is used to make a prediction and it's odd to imagine someone asking you to make a prediction about what the next day will be. The only natural context I can think of is a question asked because someone hadn't heard properly :
A : I think tomorrow will probably be quite a difficult day.
B : Sorry? What will tomorrow be?
But I wonder if you were maybe thinking of a question about the days of the week - ? In this case it's not a prediction at all, but a fact. The natural question and answer would therefore be What day is it tomorrow? / It's Tuesday.