Nintendo just announced at their GDC keynote that the 3DS Virtual Console will have TurboGraphx-16 and SEGA Game Gear titles. That is right, now you will be able to put down that battery hogging Game Gear and be able to play your titles on the go on the 3DS.
As for titles at launch, none where named. I would not be shocked at Sonic titles being the first to hit the service. Especially since this year is Sonic’s 20th anniversary.