Yeah, I was going to argue that the English needed some informality, not more politeness, but then I reread Bucket's post and wondered if I'd misunderstood the point.
Ustedes (Spanish): polite plural of "you." Closest english equivalent is "ya'll" which is decidedly informal. This is a word I not infrequently in real life find it inconvenient that english lacks.
Are you saying English need a polite pronomen or just annoyed that it's the same in both singular or plural?
I would argue that Southern US English already solved this problem. We have "y'all" and "all y'all". The former is ambiguously singular/plural depending on context, while the latter is decidedly plural.
But what about "you y'all" and "all y'all all"?
I can confidently say that I've never heard anyone say those who wasn't suffering brain damage. I have heard (and said myself) "y'all there", as a means to distinguish a plural subgroup in a spatially seperate location.
Example:
"I'm gonna bring y'all some biscuits" -- implying the biscuits are for the entire group (but group identity is contextual here...in an office setting, might just mean a specific department or subgroup)
"I'm gonna bring all y'all some biscuits" -- implying that sufficient biscuits will be brought for the entire group (so, if it were an office, it implies that everyone in the office gets biscuits)
"I'm gonna bring y'all there some biscuits" -- narrows the focus to just the people in the immediate vicinity of the person/people being spoken to
Of course, there ain't much in the way of formal grammar rules for y'all (the word, not the people on this forum) so y'all's mileage might vary.