You know this one was coming. The recently released Ice Cream Sandwich update for Samsung Galaxy S II owners in several European countries and South Korea is for the I9000 model of the phone, which is basically identical in almost all areas of the world, save a few localization files. This being the case, a public-spirited modder from Tech Splurge has posted a quick guide on flashing the software package to any GSII-I9000, saving plenty of folks weeks of waiting while their local carrier gets around to sending out the update.
Unfortunately it's a little more complicated than the standards custom recovery method: you'll need Samsung's Odin desktop software and a USB cable in order to apply the update. That said, it's probably a good idea to make a Nandroid backup to your phone's SD card anyway - anyone willing to attempt this process probably already has that capability and know-how. Once that's done, install Odin, turn off your phone, put it into download mode, connect it via the USB cable (you'll need the proper drivers as well) and flash the package. Oh, and say goodbye to your warranty.
This process won't work for any of the Galaxy S II models released in the United States, and probably not for all the variants like the Galaxy S II LTE, X, HD, et cetera. Updates to these and other Samsung phones are coming, but it could be a while. If you're that anxious to get ICS running, your best bet is probably the various ROM communities out there, but again you should probably tread with caution. Nothing ventured, nothing gained: here's hoping Android 4.0 finds its way to a phone or tablet near you soon in any case.