Nothing saying you couldn't have both. I wouldn't mind having both the Gear (since it had Map, Radio, Phone) and the Pokétch (with all its very useful abilities).

Personally, I want them to not hold back. I want Nintendo to push what the DS can do on this remake. G/S/C's soundtrack was so awesome way back when, I don't want to get a very lackluster rendition thereof (like in FireRed/LeafGreen with R/B's soundtrack). I want those battle themes to rock like they did before! The re-addition of areas that were absent in the original Gen 2 would be neat too, like Safari Zone, Viridian Forest, maybe Seafoam Islands (make you have to work to get to Blaine or something). On that note, maybe put some sort of Cinnabar Island ruins in, like the remains of some of those labs where things might still lurk even after the eruption. If they can squeeze the Sevii Islands in too, that'd be pretty neat.

And I don't mind the New Pokédex just so long as it doesn't become the Johto Dex. I mean, Johto didn't have Dex limitations like Hoenn and Sinnoh did. Let's be able to catch anything and everything from the get-go! (...just, please, no more PokéRadar. I can't stand that thing...)

After that, my requests are pretty minor. Vs. Seeker, Gym Leader upgrades/rematches (wouldn't you like to see Falkner and Bugsy with good teams for once, or maybe Sabrina with a Gardevoir & Gallade or something?), the Apricorn Balls, no more damn event items.

...I should probably go to sleep now before I go into total rant mode.