By now I've seen at least preliminary data from most observing teams and I tentatively think that we detected Namaka going into eclipse. The difficulty is that the eclipse actually takes some time -- ~15 minutes -- during which Haumea is changing rapidly.
As an example of the sort of data to be analyzed, I show below the first reduction data from the Palomar 200-inch telescope (in blue) and the University of Hawaii 88-inch telescope (in black) scaled to match each other as best I could. Times are UT the night of Jan 31, and intensities are relative to field stars.
In this plot you see about 1 3/4 rotations of Haumea. Haumea is elliptical and rotating end over end with -- we think -- one of the faces slightly darker than the other, thus the slight differences between the peaks and troughs 2 hours apart.
The expected signal of the Namaka eclipse is a ~1% dimming of the signal for ~1 hour!
Nothing is obvious by eye, so the analysis requires careful examinations of the before and after light curves. With almost 2 complete rotations we can do that comparison here. Even better, though, at least 2 observatories did observations on separate nights to get good comparison data. These give the best shot of showing something.
I think I know where the event is in the light curve above, as I also compared everything to a well measured light curve from Lacerda (though it is clear that there have been changes from when he observed). But I am eager to hear from the multi-night observations for a better indication.