Here is what Sony says about A99 weather sealing

Piginho wrote:

When you say there is no standard, what do you mean?

A previous poster made a brief reference to "IP" ratings and this is a standard for protection from ingress of dust, water etc., that is widely recognized. It is used a lot for industrial equipment, like pumps and motors, for example, but is also used for domestic products. It provides a scale of protection from splash proof right through to submersible.

If Sony were to give their cameras IP ratings, we would all be able to check the definition for the rating given and act accordingly.