Speed of light - not constant?

[dogjones]

http://www.livescience.com/29111-speed-of-light-not-constant.html

Two papers, published in the European Physics Journal D in March, attempt to derive the speed of light from the quantum properties of space itself. Both propose somewhat different mechanisms, but the idea is that the speed of light might change as one alters assumptions about how elementary particles interact with radiation. Both treat space as something that isn't empty, but a great big soup of virtual particles that wink in and out of existence in tiny fractions of a second.

Cue YECs yelling they've been vindicated. But any rational thoughts on this?

 

[BenBurch]

It is a constant in empty space. Only there is none of that around.

 

[edd]

It wouldn't be the first variable speed of light theory (counting sane ideas not creationist ones) but actually measuring a variation in it is at best extremely hard. Nothing wrong with suggesting it especially if it is a consequence of a theory with other benefits and predictions, but wait for the evidence to come in before getting too attached to it.