Watched this last night. Overall, I thought that it was well-presented. Marcus du Sautoy was a very good presenter (Although, I keep thinking that he looks a bit like the last incarnation of the Master from Dr Who...).
Within one hour we had covered prime numbers, Pi (and irrational numbers), exponential growth (e) and imaginary numbers ( i ).
The latter, in my opinion, was the weakest part as the importance of this concept was couched in the example that without imaginary numbers radar would be unusable and quickly moved on ( I guess it would have taken too long to show fourier analysis within the length of the programme).
I also got a bit annoyed at the slightly 'mystic' interludes that recapped concepts. They felt a bit like commercial breaks (Which the BBC do not have - maybe it's in preparation to sell to the US?).
I've seem some online criticism that says that the programme is too superficial. However, this series is about public understanding of mathematics not an OU lecture on Mathematics. These are two distinct goals.
I think that it will encourage people to see and appreciate the mathematics in the real world. Many people will have , for example, listened and enjoyed a piece of music without considering that an explanation of why it is pleasant to listen to is achievable by use of mathematics and understanding ratios.
So, I feel that the series is off to a good start and I am eagerly awaiting the next episode...
I was reminded by this episode how much I am fascinated by Euler's identity and how it binds most of the above concepts into a deceptively simple equation: