'toad,
Found a link for you:
http://www.earthproducts.net/products/mulch.html
Seems to be no major problems with using pine for mulch. I have been warned against using pine chunks in a wood BBQ smoker, though; apparently the resins produce an unpleasant taste and may make anybody eating meat smoked over pine wood sick.
I just last week mulched my side yard, but used cypress mulch (which seems to be most common).
(And boy, was that
fun!
)