The major effect of dark energy that we know of today would be that it can cause the universe to expand. Dark energy is known to be the driving force or universe expansion. What else could dark energy effect? This could very well effect the laws of gravity as we know of today. It may form a new view of gravity. Scientists are currently investigating if the laws of physics may be modified. This will effect Einstein's theory of gravity. Dark energy may also have an effect on extra dimensions in space. It may be likely that the universe has many dimensions beyond the three dimensions we live in and know. It is possible that these extra dimensions of space can mimic the effect of a dark energy by causing the expansion of our three-dimensional space to accelerate. The string theory is known as the theory of extra dimensions.
Dark energy may be a new kind of energy. Dynamical energy fluid or field, something that fills all of space but something whose effect on the expansion of the Universe is the opposite of that of matter and normal energy. This could be known as "quintessence," by theorists.
https://www.cfa.harvard.edu/seuforum/de_whycare.htm
http://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy/
