Games listed as "ablaze" are almost definite, "Hot" means there is discussion and a  great chance. "Warm" means that there is talking about the game. "Lukewarm" means that the game has little chance of seeing the light of day. "Frozen" is D.O.A. (Dead on Arrival.)
Mega Man 6 A possible rumor. With Capcom developing games for the N64 and the new Game Boy Color hardware selling out. There's a great chance of this game coming out. Warm
A Crave RPG My sources say yes, but any information on this GBC rpg is pure speculation. There is definite interest in a game of this type. Ablaze
Super Mario Bros. (2 - 3) The idea of porting old NES game is catching on. Hopefully these games will see the light of day. Now that Super Mario Bros. is headed to GBC; we can only hope for the other two! Ablaze
Rayman's Adventure A Game Boy adaptation of the popular Ubi-Soft limb-less wonder's first adventure could be in the works.. Hot
Metroid It would be fairly easy to do and the loss of screen size would actually benefit the game. Ablaze
The Legend of Zelda 1-2 Hmm. I see a good chance. And you know that the public will eat these up! Hot
Final Fantasy A GBC adaptation of the original game would be a good bet; because Nintendo owns distribution rights on that one. As for a new Final Fantasy game? Square has gotten too stupid to realize that they are missing a lot of money by not being with Nintendo. Hmm. A GBC re-release of the very first Final Fantasy game would be a killer way to make some money off of Final Fantasy 8's debut this year... Hot
Kid Icarus A port of the old NES game or a new title? No one knows... Lukewarm
Metal Gear Hmm. Possible ports of the original NES/MSX games. Konami is supposedly waiting to see if Shadowgate Classics, and Deja Vu 2 hit it big; before deciding to make ports of NES games themselves. Warm
Dr. Mario DX A new virus is introduced along with full color, new animation, and possible other extras. Ablaze
Game Boy Productivity Pak A compilation of useful tools; like a calculator, timer, calendar, phone book, diary, day planner, etc. Data can be passed on to other Game Boy's via the infrared port. Messages and other data can be printed out as stickers via the printer. Y2K compliant. :P Hot
Earthbound Classic and Earthbound To keep players up to speed with the series and create new hype for the game; the first and the second are released for Game Boy. Take a look at the game on SNES. It's just begging to be made in to a Game Boy Color game. Warm
Robotron/Sinistar Another "Arcade hits" Game Pak. Sounds good. Ablaze
Disney's Chip And Dale Rescue Rangers 1 - 2 The NES games gain new life, courtesy of Activision? Warm.
Activision's Atari Classics 30 old games in two 15 game Game Boy Color Game Paks. Flawless reproductions. Warm
Bloody Roar An SD fighting game. Lukewarm
Guilty Gear An SD fighting game. Lukewarm
Dead or Alive An SD fighting game with good animation. Lukewarm
Custer's Revenge What the hell? Frozen
Rush America Why not? Hot
Resident Evil Treated as a confirmed title; but no official documents or announcements have been made. Ablaze
Another Castlevania game. Do bats have wings? Warm
Puyo Puyo Already out in the Japan. A US release would be a sure bet. Hot
Tomb Raider Does Lara Croft even fit on a screen that small? Frozen
Pocket Fighters A straight port of an SD fighting game. Warm
Starfox Hmm. This one has been around for a while/ Lukewarm
Mario Kart Gamepro started the rumor with their "Lamepro" section. Nintendo still denies it in any form. Lukewarm
Starcraft Good bet! Warm
Myst Huh? Frozen
California Speed Midway may.... Warm
Faceball 2 A new game designed by Bullet Proof Software and Nintendo. Exploits a newer version of the four-player adapter. warm
July Class Reunion A dating sim game that revolves around a soccer game. Huh? Lukewarm
Pokémon Super Fight A Pokémon game that revolves around tournament fighting. Makes use of the four-player adapter. The idea is to transfer your Pokémon to the Game Pak for specifically fighting. You can enter tourneys in the game pak and also take on three friends in a fast paced fighting event with variations like Soccer and a Chess like game. You can print out certificates that you win. Warm