I'm thinking a DNA ball that increase capture rate by 20% for pokemon with legendary DNA a.k.a all legends.
They should have a new Snail pokémon and then have a random NPC refrence how he loves to eat "____" with salt.
BW2 only have the Super Rod. Compared to what? With the absence of the Old and Good rods, why not have the super rod just be called Fishing Rod? I'm hoping X and Y have just a Fishing Rod if there is only one Rod. seems strange that the only rod in the game is called Super.
An item that supresses the holder's ability!
Gen V had some really innovative items like air balloon, red card and binding band. Some were more useful than others, but they were still fun additions. I hope gen VI will have more of those unique items. One thing that might be cool is a balloon type item against fighting moves, like that you turn into a ghost untill hit, as fighting has as good coverage as ground. And of course gen IV had the type resisting berries and gen V had the type boosting gems, so I think we'll be something like that with something for each type again. Wouldn't know what though.
One thing that would be really game changing would be an item that raised speed by a % without locking you into a move. Since speed is pretty much the most important stat in pokémon, probably a lot of sweepers would start holding that.
Relay Baton: Stores the user's stat changes, causing them to be retained even after switching out, and Baton Pass also moves this item to the newcomer if he's not already holding one.
The Ladballs and Lassballs (say, 2.5x? on male and female pokes, respectively) sound good too. Some more type-specific balls in line of the Netball would be nice, as well as some location-specific like the Dive Ball. And Dawnballs as a daytime-equivalent of the Duskball.
An Item that allows you to check a Pokemon's EVs and IVs, as well as one that allows you to raise IVs.
Also, REMOVE THE LIMIT ON VITAMINS!
Something I havnt seen anyone realy talking about past evolutionary items, though its possible I missed it. If so, sorry.
Anyway, I had an idea for a set of bait-like items. If placed on the first pokemon in the party, they would draw in pokemon of their assigned type, helping you hunt specific pokemon.
For example, in an area with Elekid, Pichu, Scyther and Murkrow, 'Thunder Bait' would make Elekid and Pichu pop up alot more often than the others, or 'Wing Bait' would draw in Scyther and Murkrow, etc. Itd assist training weak pokemon by giving them an advantage, catching shineys by drawing in the type of pokemon you want, helping build a balanced team if they are available early in the game, etc.
I've always wanted some item that you can give a Pokémon to hold that will prevent the Day-Care Lady from deleting learned moves. Or even an option when giving her the Pokémon.
Give item to day care lady no more need for incense