Yesod quickstart is a basic Vagrant configuration that will create an Ubuntu virtual machine with the current Haskell Platform. It'll also setup Cabal and install Yesod.
This package will install GHC 7.6.3 and The Haskell Platform 2013.2.0.0. GHC and the Haskell Platform will be compiled. The same applies to Yesod, so expect the initial setup process to take 30 - 60 minutes (depending on your host machine and internet connection).
vagrant plugin install vagrant-berkshelf
Once the requirements are installed, you can use this like any other Vagrant VM:
vagrant up
vagrant ssh
vagrant destroy
vagrant reload
vagrant halt
If you need more information or want to tweak the configuration, have a look at the Vagrant Documentation.