Nah, DSi. Not that it matters; both the DSi and the 3DS fall under the "DS" line of systems (then again, GBC and GBA could be said to fall under the "Game Boy" line).
What we need are, naturally, new Eeveelutions (CHAMPEON!), new evolutions for older pokemon... possibly Stage 4 evolutions (3 is not enough... I NEED CHARNINATE! I don't know, I made that up....), and a Ground-type gym.
@Shefali: the PC in DPP was somewhat touch-centric, but it's a whole lot better than HG/SS's PC. And yes, Emerald's box system is excellent.