Blue Brie is an interesting cheese in that it has the white mould, Penicillium camemberti, growing on the outside (as does Camembert and Brie) while the blue mould, Penicillium roqueforti, grows inside the cheese. The cheese has a creamy consistency, not unlike that of Camembert, but with a distinct methyl ketone flavour note from fatty acid metabolism by P. roqueforti. However, its flavour is much less pungent in this respect than Blue cheese.
One method of making Blue Brie is to add spores of P. roqueforti to the milk; spores thus become well distributed throughout the cheese mass. After manufacture, the cheese can then be dipped into hot water to inactivate the spores of P. roqueforti on the surface of the cheese which is then sprayed with spores of P. camemberti. Unlike Blue cheese, which has a crumbly texture characterised by many mechanical openings, Blue Brie has a close texture that allows no air into the cheese mass. Penicillium spp. require oxygen for growth and so the cheese is pierced with skewers to allow some air into the centre of the cheese mass. The spores of P. roqueforti which lie along the channels formed on piercing then germinate in the centre of the cheese. Unlike the random veins in Blue cheese, the "veins" in Blue Brie are noticeably straight. Blue Brie is thus a mycological tour de force which helps explain its relatively high price.
Perhaps surprisingly, I am not a major eater of cheese; however, when I do buy cheese, Blue Brie is amongst my favourite varieties. A major brand on the market is Cambozola (the name is apparently a portmanteau of "Camembert" and "Gorgonzola") produced by the German company Champignon. The picture above does not do Cambozola justice; usually the surface is much whiter and has a denser covering of P. camemberti. Even if you feel the pungent flavour of Blue cheese is too much, you should try a Blue Brie like Cambozola; the flavour is much more subtle than for example a Danish Blue and should be to everyone's taste.