No, svgalib is far from dead! There are many programs around that use svgalib, including popular games such as Quake and Quake II. Development of svgalib is actively progressing, with additions of support for several new video cards and mice and other new features.
X is a network windowing system that is great for GUI apps but stinks for games and other programs that need to get maximum speed out of the graphics hardware. Fbcon is currently very limited and unstable on the x86 architecture. GGI is far from complete, and in fact has the ability to use svgalib as a display target.
In short, none of these things are going to kill svgalib just yet.