How F = ma Could Break Down at Low Accelerations

I think you judged it too fast. The article spends most of its words explaining MOND because that's necessary to present the new result:

But today, Milgrom says that he has calculated a new effect of MOND that should be measurable for planets and comets in the solar system.

The new effect is a quadropole force that repels objects in the space above and below the plane of the solar system while attracting objects that lie within the plane. Milgrom says that this should produce an effect on the precession of the perihelion of planets in the solar system.

The paper in question, http://uk.arxiv.org/abs/0906.4817, is dated June 25, 2009. I'm not a physicist, but it's clear to me that Milgrom's contribution is a MOND prediction that can be tested experimentally.

Not to mention that F = ma is just a simplification used in entry-level physics classes. The real formula is F = dp/dt, or F = m(dv/dt) + v(dm/dt), which is sometimes called the "rocket equation" (since rockets burn their fuel to accelerate, they don't have a constant mass).

And, he said it's the cornerstone of modern physics; not to be pedantic, but Newton's laws are usually called 'classical physics', while the term 'modern physics' is saved for quantum theory and relativity (check your local university's physics course catalog).

Reference: http://en.wikipedia.org/wiki/Force#Newton.27s_second_law

"But today, Milgrom says that he has calculated a new effect of MOND that should be measurable for planets and comets in the solar system," they say, so apparently there is something new to this.