His example of how things should work is pretty much 1:1 how the webhelpers.html library works in python:

    >>> from webhelpers.html import literal
    >>> p1, p2 = literal("<p>"), literal("</p>")
    >>> foo = "foo&<bar>"
    >>> type(p1)
    <class 'webhelpers.html.builder.literal'>
    >>> type(foo)
    <type 'str'>
    >>> p1 + foo + p2
    literal(u'<p>foo&amp;&lt;bar&gt;</p>')

And yes, having this sort of thing implemented at the language level, in a generic way that can apply to HTML, SQL, and anything else would be wonderful.

While we're asking for ponies, I'd also like it if "costOfPieInDollars = distanceInMiles + angleInDegrees" would be an error (unless each part was explicitly cast to a compatible type, eg the base int)...