This is the Sonic figure that GoodSmile Co. 's Nendoroid line is planning to make. Nendoroid figures are usually 'chibi' (short, stubby) versions of characters. However, since Sonic never started out with human proportions, he's sort of hard to make 'chibi' --as you can see here. It just looks like a cross between classic & modern styled Sonics, or a shorter version of modern Sonic.
These figures are known for their quality materials & good sculpting. (so expect something really nice with no paint flaws etc) They are, however, expensive so expect prices around $30 for just 1 figure. But, they usually also include loads of accessories or extra parts for the figure, such as different expression faces, different pose hands, or various little in-context items that you can switch around for cool display. This was seen at Wonder Festival in Japan.

The photos demonstrate that the figure will have alternate faces. It is likely that the bottom part of his head will be replaceable to achieve this. The photo also shows that the checkpoint post will likely be move-able. You should be able to buy from
www.HLJ.com (hobby link Japan)
www.amiami.jp
Sonic Merchandise has it for Europe too

The magazine scan shows he is well sculpted on the back too, all spikes look on-model. It also shows him with a 'thumbs up' hand which is different from the finger pointing/waving (display at right) and the 2 fists (above) Also, look closely at the photo directly to the right, his eyes are in a different position than all previous shots.
This is so far being slated for release April 2012, which means pre-orders MAY start late Nov. or Dec. 2011...so keep an eye out for this figure.

Here are the final shots, which appeared for the pre-order of the figure. You can see how the star post/gate moves, and that he comes with an Emerald & stand, & ring & stand.

This shows the various different plastic chips/cards you can put in the item container. It includes barrier shield, 1 up Sonic face, 20 rings icon, fast shoe & invincibility. The bottom photo shows the articulated/hinged stand which plugs into the back of the figure, so you can pose him jumping/running/
anything without him falling over. The emerald is quite well-sized/scaled as well.

Large Image Gallery at Japan Figure Blog and Ameblo (blogs dsc by Taaron &HM)

Official Accessory List
-Clear plastic hinged articulated Stand
-Three mouth-plates (smiling, frowning, SA1-grin)
-Two eyes (looking forward and to the left)
-Monitor/item jar with alternate plates
-One ring
-Green Chaos Emerald
-Alternate arms/hands
-Alternate leg (bent knee)
-Checkpoint star posts w/removable barrier