[QUOTE="RedDragon7, post: 5960619]To their credit, I'm not sure why this movie and possibly the next 2 are nearly 3 hours. That might be the core of the issues.[/QUOTE]
There are two reasons for extending it to a trilogy:
1) I'm not sure if you've read the book, but Gandalf continuously leaves the group to take care of other business, which is not elaborated upon at all in the book. However, in the Appendices of Return of the King, Tolkien explains what Gandalf was doing. So all of that will be shown in these movies, and that sub-plot turns out to be a pretty big deal.
2) More importantly, The Hobbit is a very fast-paced book. There's a war in the book that only takes up two pages, just to give you an idea. So in order to flesh everything out as much as LOTR, more time is needed.
So it makes sense in theory, but yes, some of the reviews do feel the movie is too long and padded.