As a student of the Dead Sea Scrolls and other Second Temple Jewish literature, I fell I must clear up a few things espoused in this discussion.
1. I have seen it stated that theories of the relationship between Khirbet Qumran and the Essenes and the cache of scrolls excavated from the nearby caves is in dispute. This is true, however reports are greatly exaggerated. While there are a number of scholars who have challenged the concensus view that the Scrolls were a product of the Essenes, by far the majority of experts still contend that the collection was a programmatic library directly connected to Qumran. Current trends in the research are pointing to a revised understanding of who the Essenes were, and how their history shaped their writings and their library (most of the texts are probably "non-Qumranic", however, they were of significant interest to the Essenes for various reasons). The group who wrote and collected the Scrolls were almost certainly a much more diverse group of ex-priests, scribes, apocalypticists, peasants, etc., than Josephus description would have us believe. Much like Judaism in general, Qumranites were probably not a monolithic group, and the effects of their history are reflected in the evolution of various doctrines in the Scrolls.
2. Despite the fact that the Scrolls and Qumran theology has nothing to do directly with Jesus of Nazareth, they are of significant interest for students of Christian origins. The Scrolls reflect a similar early Church theology in many respects, and because they were written and collected by a highly sensative eschatological group, they provide MUCH insight into a variety of NT writings and practices. For example, Jesus reply to john the Baptist in Luke 7 is practically identical to the collection of "Messiahnic prooftexts" found in 4Q521. The presence of the latter provides an historical context for reading the former.