Telltale didn't create the Samorosts -- they are sponsoring them on their site, along with a few other games.
Something similar in look and feel? I don't know -- the Samorost games are unusual. Let me think some more.
EDITAfter giving it some thought -- there still isn't any game I can think of that would be very similar to Samorost.

However, you might want to consider Gast: The Greatest Little Ghost (if you can find it) -- a review by Singer is
here. Or even The Ugly Prince Duckling, which has some of the same whimsical/fairy talesque-quality to it, and which is much easier to locate.
Since you've been to the Telltale site, I assume you've considered the Bone games? They also have a bit of the Samorost "feel," though like The Ugly Prince Duckling, the graphics are much more colorful than Samorost's.