I just found this from a Vocaloid forum. This picture is taken from a Japanese blog and it is said to be the silhouette of Kaito Append.
Here it is:
If you wonder why the silhouette is blurred, it's because Crypton said that at first they made the muffler was going to be transparent but Kaito's fans don't agree with this idea. So the silhouette is blurred because it hasn't been decided yet whether the muffler will be transparent or not.
So far, there will be four voice banks for Kaito, they are "Mellow", "Sweet", "Solid", and "Power".
And talking about Append, I wonder when Crypton will make Luka Append? Last year I heard that it will be after Kagamine Rin/Len Append but now they're doing Kaito....