This past weekend, Nintendo held a special preview event for Club Nintendo Gold and Platinum members to come and check out the Nintendo DSi, and from the event comes some good news-- particularly if you're still a little sore at Capcom never getting around to releasing Mega Man Mania for the Game Boy Advance about five or so years ago. At the event, Matthew Green of Press the Buttons and Kombo.com discovered the answer to many a retro-portable gamer's dreams, as according to the rep running the preview, Nintendo will make Game Boy and Game Boy Advance titles available for download to SD Cards inserted within the DSi, a la the Virtual Console. It seems that Game Boy titles will be made available for 500 Nintendo Points, while GBA goes for 800 Points a pop. In US dollars, that would be $5 and $8, respectively.
However, much like the Virtual Console, the first games made available for it will be as-yet unnamed first-party titles from Nintendo. And, given how long the first NES Mega Man titles took to appear on the Wii Virtual Console (with no sign of the Super NES, Nintendo 64, or SEGA Genesis titles appearing any time soon), there is no telling when or if such titles as the coveted Classic series Mega Man, the "Xtreme" Mega Man X games, the blockbuster MegaMan Battle Network, or the harder-than-hardcore Mega Man Zero titles will appear, giving those who missed out the first time a renewed chance to play them.
But, on the upside, at least now there is hope, and that's something.
Edit: In the time since this post was first made, Nintendo contacted Kombo to state that some of the information was not entirely accurate, nor officially announced for America-- at least, not yet. It seems Japan is getting the GB/GBA games, so odds are we will, too. In addition, the games will not be played directly from the SD Card.
News source: Kombo.com