Supposedly, with the December 8th update (I haven't personally verified it yet), default grid size has changed from 250 km to a surprisingly large 8000 km. You can read all about it here: http://community.eveonline.com/news/dev-blogs/grid-sizes-you/
One thing that update doesn't talk about is how gankers would often attempt to use Grid-Fu, the intentional manipulation of Eve space grids, to their advantage. This will be a lot harder to do now.
Some organizations within Eve may have considered Grid-Fu to be a valid intelligence tactic to combat their opponents, but overall, I view the grid change as a very positive change. Not only were the smaller grids often just plain annoying, they also break game immersion. This is one of those less common cases where a gank is a good thing. Grid-Fu just got ganked!
