For Grails I would suggest that anyone working on new project (ahem, you know who you are) using Liquibase (or planning to), should seriously consider using Autobase. Its DSL for Liquibase, so keeps things more Groovy and less XML (we loved stepping off the spring.xml train, so now we're in Liquibase XML fun... why?).
The HttpBuilder DSL was announced without too much fanfare, which I know we use a lot. Again, another handy tool to jump on.
If you haven't heard of Robert Fischer by now then you've been sleeping beside your pair, but his new book is sure to be a boon to us all: Grails Persistence with GORM and GSQL. Get your pre-orders in, its out on the 26th of Jan.
Another interesting looking book is ScrumBan by Corey Ladas. We're always talking about improving how we work, and the Lean folks are challenging Scrum'mers to think a little more like them.
Which brings me to my last and more unusual mention which is that David Anderson managed to convince the people at Agile 2009 to setup the Agile Frontier Stage. David Anderson gave the singularly most captivating presentation at Agile Vancouver 2008 and stands out to me to challenge (in a very healthy and practical way) a lot of the orthodoxy which Scrum has become entrenched with. He's good people, see him present!