In case anyone who in interested isn't tracking...
The 3DS, (specifically the New 3DS) has recently gotten ports of Stella, Prosystem, Handy, O2EM, Virtual Jaguar, 4DO, and more via RetroArch/LibRetro.
Emulation of these systems run full speed:
Game & Watch
Near full speed:
Interesting, but not fast enough to be considered playable:
These are not yet part of the official build, but can be found in posts by MrHuu in the thread at gbatemp. He plans to make a separate thread at some point, but as of the time of this posting, the builds are posted at page 270 (Stella, Vectrex, & Prosystem), page 273 (Handy, O2EM, VirtualJaguar, & 4DO), page 275 (Game & Watch), and page 279 (CPS3). MrHuu also posted a playlist generator here.
Also interesting is that on a New 3DS (not XL), the screen size when set to "integer" is exactly the same as the screen size on a real Lynx.