In a mere five paragraphs in yesterday’s New York Times, Neil Genzlinger writes that on January 21, the actor Kevin Bacon “turns up as the star of a new series on Fox, ‘The Following’”; that the villain of the series has “a knack for bewitching attractive women, who would later turn up dead, their eyes gouged out”; and that the series is similar to “Alcatraz,” a Fox series “in which investigators had to track down scores of inmates and guards who vanished from Alcatraz in 1963 and began turning up in the present.”
Genzlinger also writes that the bad guy “seems always to be one bloody step ahead,” but he’s probably being literal.
notoneoffbritishisms.com 
What a turn up for the book.
In my experience, “turn up” is a fairly common American idiomatic expression. Very common, actually. I wouldn’t find its use in written American English surprising, though, being an idiomatic expression, it’s not to be used in formal writing.
wulfw, I somewhat agree; but I’m finding that the informal writing all over the Internet seems to be having a deleterious effect on even the most traditional of proper-usage media.
BTW, all these turnips (pun intended, sorry) seem perfectly normal to me.