First of all both the K-7 and K-5 have many other great features besides being WR. If you are not planning to shoot with them under bad weather then you don't have to worry about having to put a WR lens on them at all.
Even if you don't put a WR lens on them, the body itself should be able to survive some water splashing on it, since all the buttons and joints are sealed. (the lens might not do so well though). As compared to a non sealed K-x, where water might seep in through the buttons when it gets hit by rain.
But of course the best overall package is K-7/K-5 with a WR or DA* lens.