Do I dare HOPE?

This morning, I noticed a bit of a bird hullabulu in the backyard around the beer box. Remember the beer box? A pair of bluebirds were fighting with a HOSP on top of the box. I went out to look and there's this nest:

Now, I put this box up as a decoy to lure the HOSP away from the bluebird boxes and the purple martin complex. Instead, the HOSP have laid 5 eggs in one BB box (which are still being incubated by the female who has no idea they are infertile) and wrens have stuffed the other one with sticks. So this box is unprotected, unbaffled, in a bad spot...on a fence near trees.
This nest does not look like a typical HOSP nest, as it has no trash in it, and it is in the more tidy BB style of a cup and not the "weaver" style.
FELLOW BIRDERS: Any opinions about this? Do I dare hope to have some bluebirds actually lay eggs??? And how, in the Hell, do I protect them? Would moving the nest laterally onto a pole make the BB abandon it? I would really like some feedback if anyone has some advice.