Surveys on Network Coding
As per Suresh's request (he is the boss after all) I am making my comment above an answer.

Emina Soljanin at Alcatel-Lucent Labs works on network coding and content delivery networks. She has written survey articles on network coding. See her web page. ect.bell-labs.com/who/emina. You can also check out her papers on content delivery via network coding and other means on the ArXiv.

I also want to say that network coding is a topic of much interest to theoretical computer science - there are several papers in TCS on this topic.