@Anon, don't worry, the Vocaloid franchise is still seeing improvements in sales over time!
Also the fandom may have moved past the 2007-9 period "trend" stage, but its not dying. ^o^
Also, Queen's right, we're a Vocaloid community, we're bigger actually then Vocaloid OTaku forums as we get more guests. That is also an active Vocaloid community.
Also bare in mind, right now there aren't many vocaloid projects in development that we know of, we have a theory going V5 is around the corner, so this is why. There tends to be a spurt of releases around the new engine release time, then for a few years. Eventually these cool down when the next engine gets out and studios focus on the next engine.
Its about this time that Vocaloid always gives the impression of a dying down period, but its not the case.