Physics World magazine is by subscription but some of their stuff is free online. This month's issue focuses on Quantum Gravity surveying string approach and loop gravity approach in a kind of balanced way The string article is by Leonard Susskind The Loop Quantum Gravity article is by Carlo Rovelli The phenomenology article (discussing prospects for testing quantum gravity models by actual observation and experiment) is by Giovanni Amelino-Camelia So it is a nice threeway split of emphasis between talk about string model, loop model, and real world testing. You can get the magazine's website by Google. It is a UK journal run by the IOP (Institute of Physics) group called PhysicsWeb. Of the three invited articles, only Susskind's is free online. But Amelino-Camelia has posted an expanded version of his article at arXiv, so that is effectively online. Interesting in the sense that it is 3 different perspectives on quantum gravity by 3 longtime leaders each of whom has a sense of the history and where the field is going. I havent seen Rovelli's but would not be surprised if it had some of the same overview as in his book "Quantum Gravity" to be published by Cambridge U. Press.