Every year there are rumors as the NFL heads toward the final day of the trading period. Most of the time, nothing worthwhile happens.

Dallas made sure that this year is different, though, by trading first-, third- and sixth-round picks to Detroit for WR Roy Williams.

This might have been the most anticipated deal that wound up coming as a surprise. After all, it was barely more than a week ago that Peter King reported having the following exchange with Cowboys owner-general manager Jerry Jones:

“We have no plans to trade for a receiver before the trading deadline.” No plans? So it’s not going to happen? “No,” he said. “No trade for a receiver.” The deadline is a week from tomorrow. Detroit, looks like you’re going to have to swallow Roy Williams in this lost season, or find someone else from which to get a low first-rounder or high two.

The move could significantly impact the fantasy value of several pretty prominent players: Williams, obviously, Terrell Owens, Jason Witten, Calvin Johnson and, eventually, Tony Romo.

Williams hasn’t been especially productive this season, catching just 17 passes through the first five games, but it’s tough to argue his talent. Williams scored at least seven touchdowns in each of his first three seasons, despite missing nine starts between the first two.

The absence of Romo thanks to a broken right pinky could lead to Williams hurting Owens’ value initially, as Dallas should look to run the ball a bit more and not rely too heavily on 40-year-old Brad Johnson. Once Romo returns, though, Williams’ presence could have the opposite effect, working with Witten to draw attention away from the Cowboys’ primary prima donna and freeing him up for more open looks. (Of course, Owens will have to learn how to beat the bump-and-run coverage he’s seeing right now, no matter who lines up on the other side of the field.)

Romo, meanwhile, figures to only benefit from having more talent at receiver. Upgrading from Patrick Crayton to Williams should make it easier for the Cowboys quarterback to find an open man once he returns to the field. To a lesser degree, the same should be true for Brad Johnson.

Back in Detroit, Calvin Johnson is getting hit with the triple whammy of losing Jon Kitna for the season, dealing with an apparent head injury and now being left as pretty much the passing offense. Why any opposing defense would afford more than cursory attention to Shaun McDonald or Mike Furrey with “Megatron” around — and especially with Dan Orlovsky throwing the passes — I couldn’t even guess.

I’d get into more detail with numbers and more specific projected impact, but you can read that sort of analysis elsewhere.

For our purposes here, the bottom line is that this year’s NFL trade deadline delivered an interesting move that will affect multiple teams within many a fantasy league.