upgrading stateless to .net 4.0. You can download the latest release via NuGet: http://nuget.org/List/Packages/stateless-4.0

Additionally, adding a few features to support concurrent processing of triggers. The idea is that for any given state machine, each trigger must be processed sequentially. But if you've got a number of state machines, there's no reason you couldn't process each machine's trigger in parallel.

There's a new ParallelExample project which illustrates a few sample approaches. This will be integrated into the main project at some point once a good abstraction is found.