A hacker by the name of Vash posted code he dug up from SEGA's Sonic the Hedgehog 4 official website on Game-Hackers.com. The code is pulled straight from the game's official flash page, and may give insight into the new episodic title heading to all big three downloadable platforms.
First, this bit of info came up in the decompiled flash code:
preorderBtn1 = new preorderBtn();
This may indicate that there could be a retail release for the game, or an alternative method of purchasing it. Given that it is a multi-platform game, there's no guarantee that this would apply to the WiiWare release, but if Amazon could do it, why not SEGA?
broniksBtn = new Sprite();
Next, we can speculate on what a "Bronik" is. Does the Eggman have an extra-evil brother? This may be supported by this bit of supplemental XML line:
<broniks text="BADNIKS" />
Next, we veer into how long Episode 1 of Sonic 4 is. At least, we can assume that's what we're speculating on, given this:
This could mean that the first episode has a total of 4 playable zones. Sounds like a decent enough length, if we assume that each zone has two or three levels (like the classic games in the series).
Lastly, we have a series of four images that don't seem to be in use for the flash site:
First, these images may be related to different playable characters in the game. As the Game-Hackers poster put it, "It could suggest a blue character (Sonic), green character (Vector? Jet?), yellow character (Tails), and a red character (knuckles)."
Even more likely is the second bit of speculation on the title: the method of delivery for the game. Blue may indicate its WiiWare release, Green is Xbox Live Arcade, Red is Playstation Network, and Yellow may even confirm a release for the iPhone/iPod Touch (which Kotaku seems to have confirmed).
Of course, the nature of the news should be taken strictly as rumor, but keep in mind that this code comes from SEGA themselves. Besides, the Sonic 4 site has a few countdown timers running, with roughly Five days *(source had three days that is for something else) until we'll see an update on characters, and 12 days until new concept art is revealed.