Went to NFJS recently. Awesome conference that I'd highly recommend you attend if you can, especially if you're into server side stuff though it was kind of nice to see the mobile additions here and there. The signal to noise ratio is always excellent. I actually used to present at the conference a loooong time ago (like, 10 years ago :). Anyways ...
Venkat should be a stand-up comedian in my opinion. He had a couple of really good talks. I especially liked his talk on features in jvm based languages (traits in scala, metaprogramming in groovy, etc) though he didn't talk much about my favorite JVM language - jython. He even mentioned tail call recursion which brought back some memories from the good ol college days :) There was an interesting side conversation on dynamic vs scripting languages but that's a never ending argument in my opinion.The concurrency talk on actor and STM based models was interesting. The Java memory model came up a few times during that talk.
As someone who has worked on both sides, the management talk was quite interesting and a bit of a refreshing change from the torrent of tech. The final shots of juice to the cortex were the sessions on Clojure and Datomic. It's always nice to brush up the state of affairs wrt lisp'y implementations.
Some other interesting items mentioned at the conference included: