I think the real importance of this study's findings is that more research must be allowed to be done on marijuana, in the US the access to government controlled marijuana for research purposes is limited, which limits research and the number of published findings like these. The fact is that marijuana is not as harmful as it has been portrayed, but we still do not know enough about the individual cannabinoids and how the body reacts when they bind to the cannabinoid receptors in our brain.
Also, i would like to point out that the harmful effects of smoking are eliminated when marijuana is used with a vaporizer, which are still fairly expensive (about $150 for a good VaporBrothers model). A vaporizer does not burn the marijuana, but instead heats it to a temperature where the THC is "burned" off and collects as pure THC vapor to be inhaled. This is currently the most effective safe way of using marijuana, but a good old bong hit is still nice.
"I don't "smoke" marijuana. I use a type of bong thank you"
a bong produces smoke which you inhale after it is filtered through water, but it does save you from smoking paper such as when smoking a blunt.
in conclusion i'd like to say that the misinformation sponsored by the US government is despicable, if they published the studies which disproved their allegations of false negative effects (gateway drug, addictive, deadly) then maybe public opinion about marijuana would be informed and policy would change.
If you are interested in an in-depth medical research report of marijuana, the US National Institute of Medicine published a report in 1999, which is one of the most recent extensive and well-known studies on the medical applications of marijuana, but also reports on marijuana in general. The report has been summarized in the book
Marijuana as Medicine?: The Science Behind the Controversy I highly recommend it if you're interested in being informed about the topic.