A few weeks ago, I had the TV on the History Channel. The Naked Archaeologist was on. I was only half paying attention to the program as I was reading a book, and the TV just happened to be on.
This archaeologist (who calls himself the Naked Archaeologist) was in a museum in Egypt examining Egyptian hieroglyphics that dated back right to the same time as the Exodus. These Egyptian hieroglyphics told a story that paralleled the Biblical Exodus. There again, I was only paying half attention to the program so I'm not sure what museum this was.
Reconstructing the past from very fragmentary evidence is no easy thing, as I'm sure we all know (I can barely remember what happened two hours ago). So any piece of new evidence can lead to enormous changes in our understanding.
The earliest (possible) reference to the Jews in Egyptian records (that I'm aware of) is to the Habiru(?) sometime in the 13th(?) century B.C. Palestine is mentioned 3 centuries earlier, when it was an Egyptian colony, but it was not then inhabited by Jews.