Recently ASI archaeologist B.R. Mani made a presentation titled Magadha and Mahabharata : Archaeological indications from Rajgir Area (via Carlos Aramayo) at the International Seminar on Mahabharata held in New Delhi in April 2012. The presentation slides are colored in such a way that humans cannot read it. Fortunately, there is a transcript which tells us that there is a connection between tradition and archaeology.
This was a place known both in Ramayana and Mahabharata. There are some structures named after Jarasandha, who ruled the place during the time of Mahabharata. Archaeological excavations done by ASI has shown that the place was developed around the second millennium BCE since Painted Grey Ware was found there. PGW is a very fine, smooth and even colored pottery with a think fabric. The people who made these artifacts knew sophisticated firing techniques and how to maintain uniform high temperatures in a kiln.
The slides also talk about archaeology in Ghorakatora and lists the articles found there. It then makes the claim that if Mahabharata happened around 1400 BCE, then there is evidence of cultural development dating to that period. When Mahabharata happened is a different discussion and so the take away is that the history of the Gangetic plains is getting updated with new data.