Interesting. Sure hope your equation holds up, because then we'll see Bitcoin pass $1.000.000 in less than 2 years (23 months). Fingers crossed 
Bitcoin reaching 1M$ in two years? Doesn't seem realistic. What equation are you talking about? The +0,75% a day?
It's not realistic at all, but it could (in theory) happen if Phil_S' graph was to be continued. Yeah it's based on BTC price = 2300*1.25^x, where x = number of months from the start of the graph.
Of course, theory is often far from reality. If the exponential amount were to hold up, it would end up in a pretty big crash in the long run. For now, we can probably expect the exponential growth to go back into a more linear fashion. This will end up reaching another exponential type curve after the bitcoin gold fork; I think a lot of people are going to sell the gold for more BTC, driving the price even higher.