Europe does use the metric system, it's presumably the developer that doesn't (in terms of countries, just the US and sometimes the UK?). Really, supporting metric and imperial should be trivial — minutes rather than hours.

The issue I see is that you aren't going to get publicity like this twice. "We now support metric" isn't news that will show up on my radar in the same way that this announcement did; how many will bookmark this and check back later, if it doesn't work for them now?