Verse vs. Prose--Playing the Punctuation

I talked earlier about the choices Shakespeare consciously made in determining whether his text should be in verse or prose.  He was one of the first playwrights to embrace the prose form, and Merry Wives of Windsor is essentially a prose comedy with less than 20% of the play in verse form.  But why choose to make this essentially a prose comedy?

He usually makes prose the language form of the commoners or the lower class in his plays, and almost every character in Merry Wives is firmly in the middle class.  In fact, Falstaff is the person of the highest class in the play, but unless he is quoting a poet, he never speaks in verse.  Prose sounds more naturalistic, more common than verse, primarily because it doesn't stick to the strict form of blank verse.  There is also a decided lack of heightened language in the prose sections.