This is a great slide deck from Benjamin Pierce, Professor Computer Science at UPenn, that shows what the world of programming languages research is doing especially in the context of types.

http://www.cis.upenn.edu/~bcpierce/papers/tng-lics2003-slides.pdf

Also from Pierce is a really good introduction (the best I have found to date) about polymorphic lambda calculi and actually programming in some of those languages. This describes the hierarchy starting with the simply typed lambda calculus (F1) and describes F2, F3, etc and Fw (F-omega). He also talks about encodings of various sorts of types and a whole lot of neat stuff. All of that written in a very readable fashion. I spent my weekend on this and it was time well spent.

http://www.cis.upenn.edu/~bcpierce/papers/leap.pdf

(For some reason this pdf seems to be back to front, but its just fine when printed)

Pierce's webpage is a gold mine of information for the PL student, including neat things like a 'Great Works in Programming Languages' list. He is also a pretty good photographer. I did see him in person when I was at MSRC in summer of 2006. I believe he was visiting those days. I now regret not having walked up to him and saying hi.