Many books and online guides on budget/project studios tell you to get two microphones: one decent all-purpose condenser, and one decent all-purpose dynamic.
The AT 2010 is a more than decent all-purpose condenser mic -- quite a good one, actually, for a very convenient price. I've used it to record live vocals, flute, and acoustic guitars, and the response and sensitivity was amazing for the price. Sure, it's no AKG 414, but for a tenth of that microphone's price, you get a lot more than a tenth of the 414's quality. For a singer/songwriter home studio, I'd recommend to get either a couple of these, or one plus a Shure SM-58, and you'd be set for recording very hi quality demos.