It's not quite football/soccer related, but it is interesting to see what's going on in other sports. This article in Popular Mechanics (hat-tip to Glenn Reynolds) discusses new metrics that are being developed in baseball thanks to video-tracking technology. By tracking the action of runners, fielders, and catchers, it is possible to quantify elements of player performance that were once highly subjective. I call them "micro-statistics" in that they don't often show up in box scores or match summaries yet contribute toward critical events in the game and eventually the final scoreline.
The company developing this technology is Sportvision, based in the San Francisco Bay Area and with offices in the USA and Europe. Most of their experience is with video enhancements to sports telecasts (the first down line in American football, the offside line in soccer), but a lot of those technologies apply well to real-time video analysis. There are a lot of data generated through these techniques, which means a lot of nuggets of information to mine and new metrics to be developed.