I have couple of suggestions for Wintergrasp.
In our realm when players join the Wintergrasp battle they are able to leave their raids and actually can invite the players inside the Wintergrasp battle. Which enables one faction or another one gather one big premade and completely dominate the battle. In our realm, Wintergrasps mostly Alliance sided. So my first suggestion is that players who leave their raids inside the wintergrasp should get kicked instantly.
My second suggestion is Horde/Alliance starting zones are kinda not balanced. The amount of time takes to reach the middle bridge to catch the initial push from defender's side is slightly longer on Horde side. So for this I suggest implementing Cataclysm Classic starting zone for each faction, when they are on attack side.
My last suggestion is that putting a definite Workshop holder reset timer, what I mean by reset timer is for example if Eastpark or Westpark was held by Alliance/Horde faction longer than 4-5 minutes or less, that workshop should turn into gray so we should actually go there and fight, this one is probably far harder than the previous two, but if it can be done it will add diversity to the way Wintergrasp is being played in my opinion. You guys might say it is not necessary, that workshop is there open the map and go take it but most of the time people disregard those two workshops and once they are capped stay capped forever.
As a player who played Wintergrasp on both factions, I think it is great content of WOTLK but sadly in our realm only one faction can actually enjoy it.
If you guys have other suggestions, please step forward and update this topic. Thanks for your time.