Making a few predictions for the upcoming remakes:
1. The third and fourth gen pre-evolutions and end-evolutions of all Jotho Pokemon will be part of the game proper, from happiny to Yanmega. This will expand the Jotho dex considerably.
2. Hu-oh and Lugia will both be catchable in game before the Elite Four. One in each game. Just like Kyogre/Groudon and Palkia/Dialga.
3. Guaranteed Shiny Gyarados in game.
4. Celebi will be released as an event pokemon.
5. You will be able to travel to Kanto after beating the elite four, you will get *one* of the Kanto starters when you do.
6. The game will contain a global trade station.
7. The Orange Islands will be in game and will contain first gen, third gen, and fourth gen pokemon that do not appear in the Jotho dex.
8. All three legendary cats will be catchable.
9. As will the three birds once you get to Kanto.
10. Kanto will be different from the Kanto of LG/FR.
11. You will be able to trade freely with D/P/P, maybe before the national dex, but guaranteed afterwards.
That's pretty much all the predictions I have for now. >.<