The future of comics starring Stan Lee and Jack Kirby's The Inhumans character at Marvel are very important to the publisher, which is why the big names of Matt Fraction and Joe Madueira were originally put on the Inhuman series. But that pressure may have contributed to what saw Fraction to walk off the book, and now Joe is leaving too.
The publisher is very worried about low sales on the book. This is emphasised by internal demands to see the Inhumans made a successful franchise at the publisher ahead of planned TV/movie development. As we have stated before, Marvel want a viable alternative to the X-Men line that Marvel Studios can fully exploit, something denied them on X-Men by the Fox Studios deal from the nineties.
What does that mean? Variants. Promotions. Any attempt to kickstart the Inhumans brand at Marvel ahead of them taking the major role in the 2015 summer event book.
As it stands the two other Inhumans titles Marvel had planned for 2015 are on hold, one starring Medusa and another starring Inferno of the Nuhumans, until the central Inhuman series does better. This Avengers NOW! promo image may have been an early iteration of these plans.
But one way or another, expect Inhuman to start doing a lot better. By hook or by crook. Might an appearance on Marvel's Agents Of SHIELD or even something historical on Agent Carter help out?