Unlikely. The first two generations needed remakes because they were incompatible with the third/fourth, and generation three's introductions of natures and abilities made a big change to the game (as did generation two's introductions in the case of FRLG). The third generation is compatible with the fourth, and probably the fifth too, and it doesn't seem like very long ago that they were released. I think that if remakes are made, it won't be until the sixth generation, or later.
On an additional note, the third games simply weren't that popular, and so may not be deserving of a remake. I know, they sold well, and have some fans, but they're generally regarded to be the worst of the generations. RBGY were the originals, they had to be remade. And GSC are generally considered the best generation so far. Do that many people really want to play through Hoenn again? Everyone remembers Lance's Dragonite and trying to beat Whitney's Miltank, but come on, who here has fond memories of say, Flannery's Torkoal? Or Tate and Liza's Solrock? The 3rd generation gets no points for nostalgia.