Mahmoud, (sorry, couldn't resist...
Thanks for the information, and I'm also fairly sure that we're going to receive a Froyo update at some time (considering that the Samsung Open Source Release Center already released Froyo sources in the "I5500XXJPG_Froyo_OpenSource.zip" archive).
There is a problem with your research, though. According to reports, around late February, Samsung disabled their web-facing FUS server. This means that end-users can no longer query for or download firmwares, and KIES 1.5 (using the registry hack method or otherwise) no longer works. Kies 2.0 is now the only way to get access to firmware updates, but nobody has yet found a way to intercept communication between Samsung's servers and the Kies client.
See: [APP] SGS Firmware Update Checker [BROKEN] - xda-developers
Anyway, TomBot (the poster who told us that Froyo is available on Kies) appears to be a resident of the United Kingdom, according to their Youtube account. If there are any UK members reading, I would suggest that you check for updates on Kies 2.0 (the latest version - older versions no longer work!). I'm from Ireland (phone is branded O2), and I'm getting the message that my phone can't be upgraded - but I assume that's because I already flashed to I5500XWJP9 using Odin.
I wonder.... will the "official" European version be I5500XWJPB? Check out the few results: http://www.google.com/search?q=I5500xwjpb