I also have a Master's degree in New Testament and Early Christianity from Harvard where I spent a lot of time studying them as well. I thought I would just repost what I did last year when slashdot ran an almost identical story. The questions that seem to arise when something like this is posted are perennial so I hope this answers some of yours or clarifies some things, and, as before, feel free to ask any questions you might have and I'll do my best to give a scholarly answer:
It's taken this long to publish partly for bureaucratic reasons, but mostly because there are thousands of fragments that are basically shredded wheat that had to be put back together, reconstructed, translated, categorized, edited, and published. This was also around the time the State of Israel was formed, and the cluster**** that was caused a lot of delays and red tape.They have not been kept secret, they have been steadily published in the DJD series (Discoveries in the Judaean Desert) for the last 50 years as this tremendous task has been accomplished. As someone said above, yes people were not very careful with them by today's standards, people smoked around them, drank coffee, and used the handiest invention that had just come out-"scotch tape"- to piece them together. All that said, with the exception of fragments in private collections, the last of the Dead Sea Scrolls were published in the early 90's.
This is not publishing anything new, or secret. It is being scanned and put online for the public, who doesn't have a clue what to do with them, can look at them. Scholars have known how to look at them, in the DJD, and in a half a dozen other widely available publications that have been around for decades.
Facts the dilettantes have said in these comments that have made me [face_palm]:
The Dead Sea Scrolls (DSS hereafter) were composed in Qumran, not Jerusalem. (some of the stuff is clearly copies of other documents that circulated elsewhere however)
The Qumran community responsible for the scrolls existed between the 2nd century BCE and ca 70CE during the Roman war.
There is nothing in the DSS about Jesus
There are, however, certain strong affinities between things we find in the DSS and the New Testament, including the method of scripture interpretation, some apocalyptic ideas, as well as the stuff you would expect people with the same basic religion, ethnicity and geography to share
There is nothing damaging or threatening to the modern religions of Judaism and Christianity. To be sure, the DSS are of tremendous importance for contextualizing their origin and telling us what life was like back then, but this is not a conspiracy to keep them hidden.