Not sure why people are still saying that New Vegas has little to explore, that's just not true. Practically all of the major explorable areas are tied to one quest or another, but there's nothing stopping you from exploring these places without doing that quest.
Actually, there is - if you want to do the quests as well. My first play through I ignored the main quest and went for a wander. I ended up breaking a large portion of the quests because I was doing stuff in the 'wrong' order. I had 3 raiders heads in my inventory for weeks, and when I finally happened across the guy who wanted them his dialogue tree had gone wonky. I went to Hidden Valley with Veronica before her quest had triggered, so I screwed that up as well. It all got a bit confusing seeing dialogue referring to stuff I hadn't been told about before.
Exploration wise, I miss all the little details found in F3. The terminals replaced the books in TES. Some are funny, some are poignant. You get a sense of history and the world before the war from them. There's only a few working terminals in F:NV, and they're short and not a very involving read.