Not that we know of. Even if all the network's computing power could be devoted to the task, it would take bazillion years to find the private key of one address by trial and error.

In theory, there may exist some magic algorithm that allows one to do that in a viable amount of time.  That would not only break bitcoin but also a lot of e-commerce and e-banking systems.  But no one has published such an algorithm, and apparently no one knows how to even start looking for it.  

[ ... ] I can not imagine many holding-water hypotheses for explaining the craziness of mining race. An attempt to crack the wallets (and I assume that for doing the trick a large pool would be needed too) would explain the completely irrational hash-rate increase.
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The bitcoin protocol gives about 3600 BTC (about 1.2 million USD) every day to the miners, no matter what.  The fraction that one miner gets from that bonanza is the same as the fraction of the total hash power than he controls.  Therefore, each miner who is making profit will want to have as much hashing power as he can, to maximize his profits.  That is the reason for the mining race.