Time to take Mirrorless seriously?

My opinion of mirrorless cameras has always been that they are more for an amateur shooter rather than to do serious work.  The sensors, are smaller and they don't have weatherproofing built in. Sony recently launched something that most photographers have seen coming for a while. A Full-Frame mirrorless shooter with HD video capabilities. Exciting news but it is still early days with limited accessories and lenses (only 5 so far). The A7R comes with a magnesium alloy body and no anti-aliasing filter just like the Nikon D800E except it weighs only a fraction of the latter. There are rumours that Canon has been developing new Foveon sensors for their own version of a full-frame mirroless. I don't think I will be ditching my dSLR anytime soon, but the future for these lightweight mirrorless bodies look promising.