NASA finds 'new earth'

That's not quite how gravity works.
By being 2.5 times bigger than the earth it might weigh 2.5 times more but because it's larger there's also a bigger increase in the radius and thus that makes the gravitation weaker.
Jupiter is like 318 times bigger than the earth and the gravity is only 2½ times stronger or so because of this.

You seem to have missed the assumption that the planet has similar density to Earth. Based on that assumption, he's entirely correct. Jupiter is a gas giant, and as we all know, gaseous entities are less dense than rocks.

We seem to be very casual with the terminologies here.

F_gravity = G * m1*m2/r^2
It matters how massive a body is, not how big nor how heavy. In fact, the larger a planet with the same mass is, the less surface gravity it has.

Just for clarification:
Heavy = how much something weighs, which is basically force due to gravity. It's erroneous to say a planet is heavy because it is more or less "floating" in space, and totally ignores its own gravity at any rate when one speaks of how heavy it is.
Big = volume. Indirectly portrayed as distance r in the formula.
Massive = how much mass something has.

Some interesting facts:
-- If a celestial object is the only object in existence, the force due to gravity would be zero at its center of mass. Yes, the core of Earth has zero gravity relative to Earth.
-- Gravity caused by a rocky planet is generally the strongest at the surface.