It won’t get new features, but Fireworks CS6 will remain available for purchase, and it will get updated to support the next major releases of Mac OS X and Windows. Check out the Fireworks team blog for more info.
History: Macromedia had effectively shut down Fireworks development before being acquired by Adobe. Adobe revived the app and invested heavily in making the app more powerful for rapid prototyping & more.
The Web moves fast, though, and Adobe has to focus. Design means making decisions, and there’s more benefit now in building new, modern tools like Edge Reflow, and in making those work well with Photoshop & Illustrator.
Fireworks is full of great features (which, as noted above, you can continue to download & use). Going forward, my recommendation is to focus on ends, not means. Fireworks lovers, tell the Photoshop & other teams exactly what you need. They’re listening—hard. Photoshop CS6 was the biggest Web/screen design upgrade in 12 years; I think you’ll love what’s arriving in Photoshop CC (smart rounded rectangles, improved type rendering, new CSS generation power, and more); and they’re just getting warmed up.