In the future tense, the use of shall and will is easily distinguished. One is always expected to use will.
In questions, it is still appropriate to use shall for first person singular (I) and plural (we). However, using shall usually carries a subtext of comedy or irony. Most use will in all cases.
The original usage of will and shall was able to carry more meaning. If a person wanted to have what he or she said carry a sense of duty or honor, he or she would use shall for the second and third person, and will for the first person. In today’s usage, the meaning would be lost on most.