Hi,

I would like to use a Traversable instance for "Either e". I have read it is a recurrent demand [1][2] to integrate it in base. Could we do it for the next release?

Thanks
Sylvain

[1] http://haskell.1045720.n5.nabble.com/Proposal-Add-the-missing-instances-for-Traversable-Either-b-and-Traversable-b-td5715398.html

[2] http://osdir.com/ml/libraries@haskell.org/2011-01/msg00325.html