Here is my source of these product codes : Samsung Mobile Firmware Queries & Downloads - Windows Phone @ MoDaCo
. Aside from the fact that the guy posting there wants to make some easy money selling something which is not his property, this excel file is a very precious source of product codes and software version :P
As seen from your other posting in this thread, German and Swedish users got some earlier versions of FroYo. However as I checked with these product codes it looks like there was not FroYo for the I5500 last night. Maybe Samsung made some tests and posted these versions by accident and users got the luck to test them. I see not reason why one regional ROM should get the update earlier than another. I think that if there is any version that would logically get the FroYo earlier should be the unbranded XE* - XEU, XEF etc.
Well, at this moment I think to make the update a few weeks after FroYo becomes available as there are some things I actually don't like in this leaked ROM : the GPS is sooo slooow & there are missing languages (no matter that I am in fact using only French translation). On the other side there are some pros like better battery usage and Task Manager. I hope to see all the cons fixed before going FroYo. At least that is the idea of the update - to have better experience using the device