The first and only video I have been able to find just posted hours ago for what appears to be an unmodified official update. The guy doesn't seem to know what differences to look for but it doesn't appear too much has changed in appearance. I was expecting to see more blue font throughout the phone and nexus style icons but I guess the added functions are what really matters
Official Android 4.0 Update For The Samsung Galaxy S2 - YouTube
Official Android 4.0 Update For The Samsung Galaxy S2 - YouTube