Achievements are great on Xbox360 - I have 53/54 in Assassin's Creed II.
But no, they won't add them in, shouldn't add them in, and if they do, I refuse to get the achievements unless you unlock something cool like the team of a PokeSpec character of your choice (obviously I'd pick Red, he has a spare Espeon).
They just wouldn't work in pokemon. It has it's own achievements, and some are incredibly hard, e.g.
-Catching a Feebas
-Winning all Master Rank Contests (one is hard enough, in Hoenn they got progressively harder, in Sinnoh you had 3 easy followed by an almost impossible one!).
-Breeding a pokemon with brilliant IVs! It took me over a week to get one with a spread of 31/30/29/28/29/31.
-RNG abuse. They do make them abusable for a reason! (Or at least I think they do).
Part of pokemon is discovering the achievements for yourself, i.e. Who's going to just happen to think "I'll visit Mr. Pokemon, I bet he has something neat" and get a Red/Blue Orb, capture the respective legendary, then think "I bet if I get both, Prof. Oak will give me an orb to catch Rayquaza!".
Honestly, I was so proud when I discovered Regirock/ice/steel in Emerald. And Suicune/Entei/Raikou in LeafGreen.