They won't buy them at this price. Do the Black S calculation and they are worth about $.55. If they get into the money by the sizable amount company may offer to exchange for shares with little or no premium or time value. These guys are very smart operators and won't do anything dumb to common shareholders. In fact I look for sizable increase in dividend which hurts warrant holders as warrants don't have a racchet feature.
You may want to check the batteries on your calculator. The July '12 12.50 calls are trading at $0.25. The warrants offer you a strike at $12 and a time horizon of Oct '14. I also think you are wrong in characterizing the warrants as being harmed by dividend payments. The dividend payments don't help the warrants with a reduced strike price after dividend payment, so they do not benefit from the dividend. However, in a small way, a dividend increase will support higher stock valuations and this will help the warrant. Higher yield supporting stock prices is true until government treasury yields start turning up which Fed has announced (how they can know?) that they will not raise interest rates through 2014.