Try changing

validy.is = function(what, str) {
    return formats[what].test(str);
};


to this to ensure it's a boolean result.

validy.is = function(what, str) {
    return !!formats[what].test(str);
};


I haven't tested this, but you don't need all the loops with jQuery.  It's set based.  You can simplify your code along this manner.

formBuilder.validate = function() {
    console.info("=== STARTING VALIDATE ===");

    var isValid = true;
    var allFields = $(".field", formBuilder.form).toArray();
    var validable = ["email", "phone", "numeric", "url"];

    var errors = {
        "email": "Debés ingresar una dirección de e-mail válida (por ejemplo: juanperez@gmail.com).",
        "phone": "Debés ingresar un número de teléfono válido.",
        "numeric": "Debés ingresar un número.",
        "url": "Debés ingresar una dirección Web válida (por ejemplo: www.misitio.com.ar)."
    };

    var failedFields = $('EMPTYJQUERYSET');

    $.each(validable, function(index, className) {
        failedFields.add(
            allFields.filter('.' + className).filter(function(index) {
                return ! validy.is(validableClass, $(this).val());
            });
        );
    });

    isValid = !!(failedFields.length == 0);

    console.info("** Status of isValid: " + isValid + " **");

    if (!isValid) {
        console.info("--&gt; Invalid field detected");
        //vw.popoverError($field, "Error", errors[validableClass]);
        break;
    };

    return isValid;
};


Using logical operators on loops results in contradiction
The power of a metaphor, I submit, is (i) the simplification of a complex idea, and/or (ii) some combination of representative elements that are meant to communicate an difficult meaning in a colourful, easy to understand manner.

In modern media, and common parlance, the use of metaphor seems to be pervasive, to the extent that I wonder if the representational purpose of the metaphor has been supplanted by the metaphor itself, and is therefore evidence of intellectual decay. I do not direct this at any particular nation or group. I observe this usage in a wide range of strata. But then, words themselves are representational in nature, although I think I can fairly say that this latter concern is within the de minimus range and can be igored. 

I notice my own increasing use of metaphors and it bothers me, and I include myself in this indictment.
