Right. Although you'll notice that I said "will" in the case of the police but strictly speaking, without seeing, I have no certainty that the ambulance didn't get there first. Whatever the truth of my assumption, for me the use of "will be" indicates a predicted outcome, whereas "would be" indicates direct information, and is more all-purpose. Both carry a relaxed tone for me.
Predicted outcome:
*knock on the door*
"Ah, that will be the landlord."
"How do you know?"
"Well, I don't, but rent's due, this is about the time he stops by for it, and I don't get many visitors."
Faced with a certainty such as the drink in my hand, the exchange might go thusly:
"What's that you have there?" (in context, Minnesotan for "Pardon me, but what cocktail are you drinking?")
"That would be a Blood In The Water." (don't know if it's particularly Minnesotan, but it suits because it ironically beats around the bush some)
"Will" in this case sits awkwardly. If we were talking about what drink is to come, I would use "will", but at least that makes some grammatic sense. In general, the whole form seems to particularly invite the demonstrative "that", and to a lesser extent "these", "those" "they", "such", etc.; usually, "it" would sit too awkwardly to be placed squarely within this idiom. But that's just how it is for me; of course I can't assume about others. Basically, I'm curious as to whether and how other people use this form, too. Why? I just get a wild hair sometimes.
![smile :)](./images/smilies/icon_smile_144.gif)
"If you take music out of this world, you will have nothing but a ball of fire." - Balochi musician