Yep, just dormant yeast. It's usually a lighter color but perhaps it's your strain. In some beers like Hefeweizen it is often desireable to mix this with the beer, imparting a hazy, bready taste.
Like Marcus said if you drink the sediment it will cause gas. It's also a natural laxative and is high in vitamin B12 - which will help with a hangover if you should drink a few six packs.