Perhaps, perhaps not. The following are two developed speculations on the topic at hand: will we ever see this black-red-orange wonder-man again?

Why We Won’t

The first, and probably most logical argument is that Shadow isn’t coming back. Sega games are full of one hit wonders, such as the extras in sonic fighters, including a chameleon, polar bear, and other such animals. Shadow could possibly be one of these. Perhaps he was just a whim of designers—who knows, we could have had a Tails-like ultimate life form… But a mirror of the main character was more appealing?

(!!!This next idea includes a spoiler. However, the spoiler is the most prominent factor in the particular theory!!!) Shadow dies at the game’s end. After defeating the ultimate life form prototype for the last time with super-sonic, they engage in the chaos control, a manipulation of time and space that ultimately acts as a teleport. Unfortunately, just as he has discovered and fulfilled his true mission from the late Maria Robotnik, he falls just short of the Chaos Control’s range, plummeting to his death through the atmosphere. I suppose he was somewhat contented at the time of his death, and his last words show his delight that had fulfilled his friend’s only dieing wish. 

Why We Will

Revisiting the one-hit-wonder tangent, some avid sonic gamers will notice that, in the very same game in which Shadow makes his debut, two other characters, thought to be dead, were available for play in the two player treasure hunt. These were the Echidna Tikal and Chaos Zero, whom both made a seemingly one-time appearance in the Dream Cast game, Sonic Adventure. And to make a long story short, they both end up pretty much dead. Note: this only applies in the Sonic Adventure 2 Battle game, which is a slight update to Sonic Adventure 2, which does not contain a two-player mode.

Perhaps Shadow will end up in the same sort of 2 player mode – he’s dead, so he obviously not be a major part of any plot (but then, he could come back in some magical and plot-turning vision of Sonic’s in a future game!) – but there’s always the possibility of more Shadow! And I, for one, am hoping very much so to see him again.