I love sliding tackles, and they'll be a key ingredient in WOF. Our inspiration is, as mentioned before, Kick Off and I've always preferred the unrealistic but fun KO sliding tackles to the 'impotent' tackles in FIFA/PES.. With sliding tackles you can not only chop an opponent down, you can also hit the ball, keep it in play or stab it into the goal.
Fivemagics implemented the tackles yesterday and now its being tweaked and polished (a longer on-going process). Below is a movie showing the tackles in its first iteration. Oh yeah the guys fall over too - and you'll be able to scythe your team mates down also! 