If you've been crossing your fingers for Super Mario All-Stars 25th Anniversary Edition in the expectation of it receiving a PAL-optimised conversion, you can unbend them and start using them to type vitriolic comments now – the package will not be 60Hz compatible.
Below is the response reader XD375 received when enquiring with Nintendo Customer Service:
We have now received a response to your enquiry from our European head office. Unfortunately, the European version of Super Mario All-Stars runs the games at 50Hz and not 60Hz.
If you're not sure why PAL 50Hz is a problem, our article Talking Point: The Virtual Console's PAL Problem could be enlightening.
Super Mario All-Stars 25th Anniversary Edition lands in Europe on December 3rd.
Thanks to XD375 for the tip.