Long distance relationship

I'm in a LDR and will have to be for at least another 2 years minimum, everythin is going great but is distance reason enough for breakup after dating for 2 years ? I'm afraid it will get to be too much and I should end it sooner rather than later if the distance will be too much for that long. I have graduate school and he doesn't and I graduate from undergrad a year before he does. The distance is only 2 hours but it could be more after I apply to graduate school next year...