Strongly-typed dictionary/hashtable

The hashtable provided by Boo.Lang attempts to mimic Python semantics, but by defaulting to a mapping of Object to Object, forbids an entire class of operations to be performed directly (unless duck-typing is globally enabled). It is rarely possible to operate directly on the contents of a hashtable, without explicitly downcasting the stored type.

I would like to see a generics-based hashtable (presumably a subclass of System.Collections.Generic.Dictionary), which mirrors as closely as possible the syntax of the existign hashtable, while allowing the programmer to specify both key and value types (along the lines of array(), which provides typed arrays).