@Respawned Fluff, will you say that the voltage divider R1-R2 in the transistor circuit below creates a virtual ground?
There is a lot of philosophy in this topic...
To make a current flow between two points inside a circuit, we must create a potential difference (voltage) between them. For this purpose, we keep the voltage of the one point (the ground) constant, and change the (input) voltage of the other point. So the ground is the other point, not the input point.
"Ground" makes an association with something stable, solid, stiff... that does not "move" when we change the input voltage from the "other side" (or source/sink a curent to/from the ground). So, this point may have any voltage (to be a "shifted ground") but obligatory it must be low resistive enough... just to call it "ground".
So, here the voltage divider output does not serve as any ground... it produces another input (bias) voltage... it is another input voltage source. Thus we have two voltage sources connected in parallel to the same point that strive to set its voltage.
The one of them (the voltage divider supplied by Vcc) is permanently connected (no matter of the frequency). It is a "bad voltage source" (having significant output resistance)... or more precisely, it is an "intentionally worsened voltage source". So, if you still want to think of it as of a kind of virtual ground, you can name it "intentionally worsened virtual ground".
The other (input) source is perfect... but, at low frequency, it is "disconnected" (by the capacitor) from the common point... and it does not affect its voltage that is set to 1/2Vcc by the imperfect voltage source (the voltage divider). At high frequency, the capacitor "connects" the perfect input source in parallel to the imperfect one... and forces its voltage upon the common point.
This is the biasing trick here - at high frequency, to connect a "strong" (AC+DC) voltage source to a "weak" (DC) voltage source.
Another unconventional viewpoint is to think of this arrangement as a voltage summer with weighted inputs (applying the superposition principle). The input from the side of the voltage divider has relatively low but constant weight, while the input from the side of the input source has variable weight (big - at high frequency, and small - at low frequency).