I've updated my binary package for Allegro 5 to version 5.1.10. It was compiled with MinGW 4.8.1. You can find the binaries for each of them here :

https://sourceforge.net/projects/unofficialmingw/

https://sourceforge.net/projects/unofficialallegro5distribution/

Hopefully this will make it even easier to get started compiling with Allegro.

To use the binaries simply extract each .7z file twice. You can download 7-zip for free at their website :
http://www.7-zip.org/

Once extracted, set your path to include MinGW\bin and you are ready to compile C and C++ programs. To use the Allegro 5 distro, set your compiler and linker search directories to A5110distro\include and A5110distro\lib respectively and then set your project to link to the desired Allegro libraries. Static, Dynamic, Debug, and Release monolith versions are included as well as all dependencies and dlls necessary to compile Allegro 5 programs. All examples and demos are included and statically linked. Source for the library, examples and demos is included as well. (Edit - if you haven't tried the demo programs yet, you really should, they are all great examples of what you can do with A5. That and the examples too.)

If there is enough demand for a more recent version of MinGW I may be convinced to put new binaries together.

Happy coding!