Hey Jens,

The last real market stats published and available to the public can be found here:
Professional 3D Market Stats

However, these are dated to 1999, so things have no doubt changed since then. How much have they changed? Impossible to even speculate. Good marketing on a company (such as Alias) can easily lead to misconceptions. Alias|Wavefront's Maya is a great application - its modeling is top notch. However, it should be noted that many studios who use Maya for their work, specifically model their objects/characters in LightWave first (then transfer them over to Maya for animation). Take that as you will.

Personally? I'd stick to what you knew! Rhino (superb modeler) and Cinema 4D for rendering. Unless the client wants the raw files in a specific format (Maya, 3DS, LW, etc)...then it shouldn't really matter.