Someone has seen a model that is being said to be the Onager Dunewalker for the Skitarii that are rumored be coming in the near future. This was said to be a heavy support choice previously, and from appearances below, seems to come with several weapon variants that the source was unfamiliar with. With overlapping shields mentioned previously, and variable weapon options, this looks like it will be an interesting release.
Please remember that these are rumors. here is a compilation from various sources by following the link. http://natfka.blogspot.com/2015/01/adeptus-mechanicus-compilation.html
via an anonymous source on Faeit 212
Ive seen the model so I thought I would chime in and describe the Dunecrawler. Sorry no pictures, it was not possible.
Its a walker with 4 armoured mechanical spider legs. The crew compartment is large metal box angled in the front. There is a small robotic arm in the front with tools and drills on the appendage. The visor for the drivers inside is a slit with optical lenses on the the left hand side of the opening. The Eradication Beamer is big, and looks like a giant conversion beamer, up top there is a gunner with a heavy stubber. I don't know the optional guns, but there are a couple. One that looks like a long barreled autocannon, but has some sort of array attached to it. None of the weapon options look like standard Imperial Weapons.
I also wanted to mention, that this is a Games Workshop release, not Forgeworld.