When I wrote "speed up" I meant "speed down" :) just a bit mixed up here.
We could be lucky that with HD the PAL speed up is almost a matter of history, at least a fading part of ancient Video times...
This post is off-topic to DOTD but relevant to DVD audio vs blu-ray audio.
Unfortunately the problem of incorrect audio speed is not entirely solved. It is fixed for blu-rays of movies, but there are still some problems with TV shows that are dubbed to another language.
As you might know in germany everything gets dubbed and everything released domestically includes at least the german and the original audio track. The problem with TV shows is that these are dubbed for TV at 50Hz and broadcasted this way. When this show is released on blu-ray the disc can either be at 50p with the correct german audio but incorrect original audio or 60P/24P with correct original audio but incorrect german sound.
There are several blu-rays with this effect, sometimes it even happens with big budget movie releases. The german release of LOTR EE is a well known example. The original german DVD release of LOTR EE had pitch-corrected audio at 25fps. This was slowed down to 24fps for the initial blu-ray release. Warner Home Video has fixed this and you can replace the wrong discs, but it shows that there are still some issues left.