It's a great time to try Sketch: http://www.bohemiancoding.com/sketch/. Does most of what Fireworks does much better. Unfortunately it's Mac only though.
It would be great to see Sketch available for the PC. In the meantime, for of those on Windows, I would recommend trying Xara Photo and Graphic Designer.
They have a free trial, but they are actually giving away an older version of the software for free until 20th May 2013 (in the hope that users will upgrade, no doubt)
Xara is more of an alternative to Illustrator but it includes some basic bitmap manipulation tools.
I have used Xara for many years and, in my opinion, it has a much better interface than Illustrator and is much more responsive in terms of screen redraw and speed. It's not completely equivalent to Illustrator in terms of features, but I would recommend downloading the trial (or the free version) and trying it out to see if it's suitable.
I've been a fan of Fw for many years and now primarily use Sketch. It doesn't have the raster capabilities of Fireworks (Pixelmator's there when I need to work w/ bitmaps), but it has the same concept of Stylized Shapes and Shape Groups instead of Layers.
Lately I've also enjoyed its "Copy CSS Attributes" feature for building linear gradients or shadows visually, then getting code which I can quickly use in browser.
