Well I think we should prepare for this. At this time its not an urging issue, as the hashrate is growing, and there are plenty of space to increase the diff, but once hashrate is not increasing, or we get a very high diff, the chance of getting the same hash is getting bigger.
Even if you use up all energy of our sun, you won't be able to find a collision by chance
The only possible scenario is when SHA256 is completely broken