Afonic DVD Guides Calc v1.0.0
www.dvd-guides.com
I know this one is very basic, but I am using it for my own needs, and since some users asked for an MPEG2 bitrate calculation I post it here.
NOTE: Please report any errors in Afonic DVD Guides forums. The calculation is fail safe, which means that 100MB or so in your DVD will be left empty. Next versions will include many more features!