IP*8 is waterproof, IP*2 means it is safe to use in rain falling at no more than 15 degree angle. Seems fit for purpose to me, since one wouldn't normally carry out scheduled inspections when it's pissing down in a howling gale.
The first digit, in the case the 5 in IP52, refers to object / dust ingress. 5 means that whilst dust might enter it, the dust won't bugger it up.
Still, it seems to be largely a development platform at this stage; organisations might buy a couple of this gen to play with and code for.