There are some great pieces, all new, that reflect the origins of stencil activist artwork, including his classic Beggar. Worth checking out, especially if you have any interest in where Banksy got his groove on.
Beautifully, Blek has been out in Shoreditch, promoting his show with some new additions to the Hoxton canvas like the classic Sheep above - ambient advertising to promote a show by the guy who helped invent the idea of street art as art, which has been subsequently adopted by so many brands seeking credibility in their communications.
How many posts can you prefix modern with?
UPDATE: You can see more of Blek in action here.