The phone in appearance is virtually identical to the Galaxy S3 (regular?) version, but obvious a bit smaller. Depending on pricing and whether it ever hits U.S. carriers, this could be a nice gap filler for Samsung to those folks who can't/don't want to shell out the premium pricing for the full version of the Galaxy S3, or simply don't want a 4.8" screen on their smartphone, but do like the form factor and design of the Samsung flagship line. You've probably read the reviews of the Galaxy S3 on this site and perhaps in other places. As someone who has seen and played with an S3, its a really nice powerful phone that is some of the best of what Samsung and Google's Android has to offer.
If you live in Germany, look for it at a Telekom near you starting tomorrow! If you are in the U.S.A., you may have to wait a bit longer.