The first one is a tighter integration with some of the web frameworks available in Haskell-land. In particular, you can create Snap and Yesod projects directly from the New Project wizard in Eclipse, provided the neccessary tools are installed. Also, I've linked some content-types to existing web editors, so you will get HTML editor for a Heist template, CSS editor for a Lucius template and so on.
The other feature that most of the people requested was autocompletion. I didn't implement that before because my knowledge of both Eclipse and Scion was lower, and didn't really know where to start. But after these 3 months I've been able to come to a solution to the problem, and I'm delighted to present the new revamped Haskell code assist for EclipseFP:
In the following days I plan to implement more of the suggestions in my TODO list :D