The accuracy of emulation has absolutely nothing to do with when the device the emulation is running on when made. The performance might, but not the accuracy. Note that I worked for the leading emulation software firm of the early-to-mid 90s and actually know what I'm talking about. In fact given enough time and Nintendo documentation (that may not be available), I could make an accurate SNES emulator that runs in a 1995 Power Macintosh. It would be FPS-challenged, but it would run and be accurate.People should stop expecting full accurate emulation from a 2009 device.
But I'm not for spending a lot of time working on a emulator for a minor platform like the DSi. The 3DS makes sense. It can run DSi games and do something no other handheld in history (or today) can do: 3D. The New 3DS XL, with its faster processor (that can actually run reasonable PS1 emulation, and unlock 60 FPS on 30 FPS 3DS games) is the ultimate handheld because of how many games of the past it can run natively, how many it can run in emulation, and how no other device on Earth can run its 3D games in 3D. To me that is where traditional Nintendo handheld emulation efforts should be made.