It's going to be Ed, Caleb or Tahan tonight. Most likely Tahan. That said, BBAU has a huge female demographic skew, so the former two might end up getting saved out of their asses. That still leaves Tahan, though.
I don't think Tully or Tim will be going, both for the same reasons -- people know what's good for their TV.
If you look at this series' evictions so far, there's a very clear pattern of underrepresented/quiet HMs getting evicted (sans considering the females voting for the eye candied but boring housemates, i.e. Matt). Every week has been predictable thus far. Sharon, Rohan, Jasmin and Xavier's evictions in their respective weeks did not surprise at all.