As a preliminary solution, I am currently using the Nuclex framework (see note below) in an C#/XNA game project for buffered keyboard input. Sadly, Nuclex relies on SlimDX.Directinput.dll and therefore to my knowledge can only be used under Windows OSs. However, I use MonoGame to target other platforms (Linux, OSX, etc.) and therfore I am looking for a portable way to integrate buffered keyboard input aross all platforms. Is there any?
Note:
This question originally linked to Nuclex on CodePlex, which has been in archive mode since 2017 and will be going offline soon.
The link now provided (mirror) goes to a copy of last version of Nuclex posted to CodePlex.
Cygon appears to be maintaining development here.
A different branch is available here.