At Edweblogs.org: NECC 2004, there is an entry on Bernie Dodge's presentation about the evolution of webquests.
It seems that one of the criticisms levelled at webquests is that they should be more interactive. Bernie himself has his students write blogs. He says he gets to know them better that way. There is more about his presentation here, hinting at how to integrate blogs and wikis into webquests.