Many gameplay elements can be easily added, and It would be nice to see people being pro active than negative about the game. I bought 2012 having never played the 2008 version, But I am quite aware that 2012 is a somewhat cut down version with a few extra features such as battleground states. But most of the pieces are there for anyone to add new content to the game, and It would be really good if we could get a modding community around this game.
Simple Xml editing is obviously possible, allowing you to add lodes of new content, such as replace endorsements, add new random events, change stats, remove features change state names, change party details.
Yes you could do all this in 2008, but, they are selling this game at a reduced price from the 2008 version, as they are aware that it has "less content" by focusing on just the US presidential election. So yeh, this game is probably better for people who didn't play 2008, but why not get pro active, and add some content yourself? Its not really very difficult.