I probably won't buy on release and will wait for enhanced or whatever it will be.
I'm actually rather tired of dlc and enhanced editions even if its free. I buy all these games for $50-$60 and then I'm afraid to play them because I know they'll be dlc or enhanced edition 6-12 months later and I don't want to miss the extra content but I also don't have the time to replay every game 3-4 times. By the time all the content is released the game can be had for 1/2 to 1/4 the price and I regret my full price purchase.
I want to support my favorite dev's with a day 1 purchase but I don't want to support buying a game and the waiting a year for the complete version.
Sad thing is, I was pretty excited about the potential of dlc when it first started coming out. They could add real gameplay enhancing content, I thought. For example add 10 classes,25 monsters, more skills, better AI and increased difficulty levels or a 3-5 hour focused and amazing quest that adds elements that weren't released in the game. Unfortunately that hasn't happen for the most part.
I was a habitual day 1 buyer and now I'm considering waiting 6 mo to a year. I don't think this was the developers desired effect with dlc, I wonder if enough people will start to feel this way to actually affect the dev's pocketbook.