These are the most popular ideas from the pokemon community so far (and i agree with all of them):
• Paretal Bond nerfed from x1.5 to x1.3 attack boost.
• Rock Slide accuracy increased to 95% with a flinch chance of 15%
• Delete the secondary effects from Thunderbolt, Ice Beam and Flamethrower (these moves are already strong and COMMON moves and they don't need a stupid 10% chance to change a match such as freezing a Heatran with a random Ice Beam or paralyzing Ludicolo when you just to deal chip damage on it with TBolt)
• Ban Dark Void and Minimize
• Keldeo, Genesect and Deoxys introduced in the format.
• A limit of 3 legendary pokemon in a team
I have little experience with the format so I am the last person to say what has to change. But here's a thought:
I believe that Gamefreak should experiment by making the season 11 battlespot rules the official VGC16 rules. Reading those rules it sprang to mind that the company might be searching for a rotation system a bit similar to a card game. I'm a bit curious to see what will happen to the game if a system would be installed where the top X most popular pokémon from the last 2 seasons are not allowed to be used. Will it be more entertaining for anaudience that wants to see a more obvious variety?
What I've seen in many card games is a rotation system to keep the amount of cards to choose from limited and strategies "more alive" (as those companies like to say). Old sets rotate out and new sets come in, popular strategies aren't as viable as they used to be since the strong cards eventually rotate out of the format and new cards offer new (and sometimes better) options. Players are forced to constantly adjust and change their decks and strategies..or wait for a reprint and hope those cards are still usable then.
This may also be a viable system when applied to a video game series as long-lasing as pokémon. Pick the top 10 most popular pokémon from last season and don't allow them to be used for 2 seasons before rotating in again. By the time a new game comes out with new mechanics, strategies and adjustments they pokémon that rotate back in have to be used diffrently than the last season they were used. Of course a card game is different from a video game, but looking at the season 11 battlespot rules makes me think Gamefreak is experimenting with something similar. I thought Gamefreak was already trying to go in that direction when they introduced the KallosDex only rule in 2014.
Personally i feel like the rules for VGC 14 where the best, i like the no legends as it means players have to be more creative in moves, spreads and team builds. i mean just look at the master division this year, everyone ran pretty much the same team where as in 2014 we got introduced to pokemon like pachirisu which changed how the game was played massively and now you hardly see teams without a rage powder or a follow me pokemon. no legends would also allow some pokemon to become more viable and not get stomped out easily