Oh. That's a bummer. We really loved playing Clonk Rage and previous titles in splitscreen. In fact, Clonk is played here among family and friends since ages because it offers such a great range of gameplay - settlement, racing, fighting ... There is nothing you can't get with clonk. And there is no greater pleasure than playing together with your friends sitting right next to you. (I can remember whole afternoons spent with clonk together with three friends on one computer ...). Splitscreen is surely the main reason we are still playing clonk.

Are there any plans to repair splitscreen and put it back in the game?

But besides the splitscreen problem, I really have to say that OpenClonk looks very promising. I like the look of the game, especially the background image of the main menu in the dev snapshot. It looks bright, shows you some really clonky landscape and somehow invites you to play (things I couldn't say about that blurred background image of the stable release, I think its good you replaced that one ;) )
My little brother spent hours this morning playing in singleplayer and will definitively continue playing :), so I can't say much about the gameplay at the moment. He hardly gave me a chance to try it myself ^^