lol. Stealth Rock isn't that big a change for anyone besides competitive battlers. It's forgotten in casual play.
Everything fell in place in Platinum. Many Bug Pokemon got the long awaited STAB (even if it was Bug Bite, better than nothing). Many Other Pokemon got very reliable STAB as well as a usable move pool, i.e. Gengar, Misdreavus, Hitmonchan....
I want to see Fog as a new weather condition....
I don't think a Castform evo will happen.....If it did, that would be awesome (and I would abuse it on almost all of my teams, lol), but I don't think they will, IMO.......
A 5th moveslot / 7th Party slot won't happen. IMO, battling is nice w/ 6 vs 6 and keeping Infernape / Pory Z / Gengar / Lucario from being too uber....
Contests and the Pokelathon need wi-fi.....Pokelathon is great, and contests would be worth the effort of getting special Pokemon for if there were others to play w/.....Maybe add it to the new Stadium game for Gen 5 (and if the stadium doesn't have mini games, many will be upset. The origional stadium games were praised for them.....).