The article says that the this meat is created using stem cells from slaughtered animals:

Using stem cells harvested from leftover animal material from slaughterhouses, Post nurtures them with a feed concocted of sugars, amino acids, lipids, minerals and all other nutrients they need to grow in the right way.

When it comes to nullifying something forbidden that is mixed in with something permitted, there are several conditions that prevent nullification. On of them is called a Davar Hama'amed. From the Star-K's website:

A Davar Hama’amidis something that “creates” a particular product. A classic example of this is non-kosher animal rennet used to make cheese. Without the enzymatic reaction caused by the rennet, there would be no cheese. Hence, even if the milk is sixty times the rennet, the finished product is not kosher.

It is possible that these stem cells would be considered a Davar Hama'amed, since the whole concoction is dependent on the stem cells to exist. Since a Davar Hama'amed is never nullified, it doesn't matter how minute the stems cells are, they would still make the final product meat, and therefore subject to all the regulations thereof.

Thoughts?

It would seem that the only way around this would be if the stem cells came from the bones of the animal (not the bone marrow). As described here, bones are not considered meat. However, I'm not sure stem cells can be extracted from bones, it is not listed as one of the sources of stem cells, here.