For those of you who can’t wait, here’s “leaked ICS ROM” you can try, which is pretty good with everything working for your Galaxy S2 i9100.
After trying this ROM, it seems like the Galaxy S2 is a really good candidate for ICS and everything runs smooth. It is a bit buggy and you will get force closes sometimes but other than that, everything works and smooth otherwise.
To install this ROM, you will need to use ODIN to flash the files for it, you can see a tutorial video here for that:
And downloads here: