hopefully he's been gathering up great new effects all these years to show in a new tv series, and performing these endurance stunts so his fame isn't lost in the meantime. I'm sure its very difficult to come up with new routines, I doubt he has the immense staff Criss Angel has which includes the likes of Jay Sankey and Luke Jermay just to name a few.
David Blaine would never do a TV series. He's been leaning away from magic for quite sometime. He's focusing mainly on his stunts. That's what he wants to be known for. Which is why he does all of the stunts.
Now, lets say for some reason, he'd do a TV series, he would be able to get better consultants then Criss Angel. Simple because he makes quite a bit more then Criss Angel (nearly 2 million more, if not greater). And David Blaine has many connections, including Paul Harris. So, the reason he isn't doing a TV series, is most likely because he doesn't want to. It simply wouldn't fit him.