I've been doing arch vis in an Architecture firm for going on 9 years and I am getting busier. I have 3 other arch vis guys and a graphic designer. There is always the steady image requirements for council applications, we have been pushing doing as much of the marketing material as possible in house, and with the difficulties in getting architectural jobs we have been doing a helluva lot of hard and fast punt jobs with a hero shot or too, these can actually be quite fun.
We have been Archicad based for 10 years. When a 'good' rendering engine was incorporated into Archicad a while back a few thought they would be able to do what the pres. unit guys can do. I think it was soon realised its not just applying materials and hitting render. I also took it as a motivator to further distiguish our quality and output from the render button crowd. As mentioned above, get artistic and use different styles. For me it is great as more of our office can model well (I get to help steer them for my benefit;) materials breakup etc.), this has freed me to concentrate on the image.
As mentioned above as well, expand your services with VR, animations, interactive media etc. It all helps! And yes, the reality is that financial returns just arent as good as they were...