253 BTC (250 of which was bet last night) says that Butterfly Labs (BFL) will not be able to deliver their ASIC product prior to the 1st of March. The bet itself does not close until the 22nd of February (a bit strange), which leaves plenty of time for people who disagree with the "no" side to place a counter-bet.
Bets of Bitcoin has a similar bet on their site, stating, "Butterfly Labs will not ship ASIC-based BitForce SC products before April 2013. 59 BTC are on the "yes" side while 184 BTC are on the "no" side. In other words, the predictions market on Bets of Bitcoin is optimistic that BFL will deliver before April 2013.
Between the two markets, the consensus seems to be that delivery will take place sometime between March 1st and April 1st. If that turns out to be the case, it would be a major disappointment to anyone who had placed a pre-order with BFL, especially since the original promised delivery date was three months ago, back in October.
Bitcoin predictions markets are not as well developed as they are on a site like InTrade, for example, but InTrade is notorious for being able to predict all sorts of outcomes quite accurately, the most significant of which was the recent US presidential election. We'll have to wait and see if Bitcoiners are equally as clairvoyant.
Edit: A good point was brought up on the forums by Frizz23. If BFL knows they can beat the March 1st deadline, we should see someone from the company throw up a 250 BTC counter-bet in the coming weeks. If not, well then I guess we'll know the truth!