Here are some programs I made that will set the resolution of the game in 16:9 ratio.
http://www.area51cheatserver.com/Minecraft_HD.exe
Now I know Xfire doesn't work but Fraps does. If you know any other recording programs, comment in here.
Example of using the program.
http://www.youtube.com/watch?v=6FfPj8OPorM