The Ninja is composed of four parts, a head wrap (part x54), head, torso with gi print, and black legs. The head wrap has been most recently seen on the "Cairo Thug" from Indiana Jones, the gi print on the torso is very similar to the Jedi minifigures from Star Wars. The torso print appears to have less "detail" than some of the original Ninja minifgures. The 'squinty face' design on the head is new.
The accessory is a pearl gold katana (part 30173), that has also been seen recently in Indiana Jones sets. As always, the figure will come with the new minifigure stand.
Army Building Potential
The "army building potential" or "ABP" for this figure is high. Ninjas don't really need a lot of additional customizations or changes to fit into a Japanese clan. In some ways they are similar to Clone/Stormtroopers.
Feeling It Out
This figure might be difficult to identify through the packaging with no obvious features or accessories that can be ID'd via touch.
The following are the secondary bar codes that can be found on the back of each bag which indicates the figure inside. The bar code on the left is valid for the EU while the bar code on the right is valid for the US. These bar codes come courtesy of Brickset.com where a single pdf containing all bar codes can be found.
FBTB.net Poll Standings
According to the poll currently on the FBTB.net forums, The Ninja is not faring well in the votes, and I'm beginning to see why. A lot of the pieces for the figure can be found in recent sets (Indiana Jones, Star Wars). There really aren't any unique elements like the ray gun that comes with The Spaceman. As always, those who frequent AFOL forums may not be representative of the broader market.
Although I like the ninja as a "concept", TLG could have done more here than simply rehash some old parts. It would have been great to see a new accessory or weapon here to increase interest. I'm sure minifigure accessory customizers would be happy to oblige.
Official LEGO.com Bio
“Like a shadow in the night, I – oops!”
Stealthy. Sneaky. A cunning master of martial arts. None of these things describes the Ninja, although he sure wishes they did. He tries his best to dramatically blend into the shadows or hide in plain sight like all the other ninjas can, but no matter what he does, he always seems to mess things up. The truth is that he’s just plain clumsy, and no matter how gracefully he may start a back-flip, creep along the rafters or launch himself into an epic sword battle, he always manages to trip over his own feet, fall off the ceiling, or bonk himself on the head with his ancient and mystical blade. Also, he’s afraid of the dark.
No one is quite sure how the Ninja ever managed to graduate from ninja school. But no matter how bad he may be at his chosen profession, he always keeps trying and never gives up, convinced after each blunder that the next time, he will prove himself a true ninja warrior for the ages.
(Pictures from FBTB.net and Brickset)