I prefer the style of using names for optional parameters. Certainly in this case, as I already said, adding -parameter to parameter::get foo isn't making things any more clear. It's not really good tcl style, either... I'm all in favor of making things easier to learn but pretending we are OpenACS for Dummies is silly because we obviously are not.
As for the "if we use named parameters in one place we should use them everywhere" argument, I'm sure you're familiar with the Emerson quotation about foolish consistency and little minds. :)
In any case I think it's clear developers are voting with their code.