If your water heater is more than 10 years old and/or you are considering replacing it, now is the time to do it.
Effective April 16, 2015, Federal regulations will require water heater manufacturers to produce more efficient units. Making them more efficient is going to make them wider, taller and up to 25% more expensive.
If your water heater is a tight squeeze now in your closet, the units required after April will not fit causing them to be either relocated or closets reconstructed to be bigger.