What locomike says x2. He hit the nail right on the head. They are a great fun bike, and pretty cool for extended trips with the six gallon tanks. I know a guy that picked one up on a whim, and liked it so much he sold his custom Harley, and never looked back.
Based on the last time I really played with or looked through bikes, if you want something with a more 50/50 street/dirt orientation, I'd look more towards the XR 650.
If you want a VERY dirt oriented dual purpose, I'd suggest taking a gander at the KTM's
Nothing wrong with Suzuki's either, but just wanted to name a few main options regarding streetability and dirt ability. It's been awhile since I've thrown a leg across a Suzuki, but I seem to recall them being slightly more dirt friendly than the XR.
There's usually some kinda buyers guide or dual sport issue in "Dirtbike" every month or two, if not there than some of the other mags. Might be worth investigating as well. (be forewarned, my thoughts and information are a few years old now)