The PAL and NTSC difference isn't absolute 4 %, but some decimals also. (PAL 25 and NTSC 23.976) but I don't understand the initial request on first place, because nobody sane does PAL <-> NTSC conversion by speeding up the playback.
If I am watching a PAL movie my playback is 4% faster than someone else's who is watching an NTSC movie. If I slow my movie by 4% then our movies run at similar speeds. Without the slower playback my movie runs almost 5 minutes ahead of theirs by the end of two hours.
The fact that it isn't exactly a 4% difference isn't important, it is close enough. Now the difference in speeds will be within one minute finishing time of each other instead of several minutes. So it is a great change and I look forward to the 1.0 releases.