Since it's a popular manga that's still in the middle of being published with a large amount of material to adapt, UQ Holder was prime real estate for an anime adaption. I'm not that surprised that they decided to finally animate it. UQ Holder was one of my 100 wishes on my anime wishlist, and now it's been fulfilled, so I'm very pleased with this announcement. However, it was hardly a high priority item. Until Negima's been animated, UQ Holder makes no sense to animate. Everyone who will be watching this show will be totally lost because they don't know any of the characters. But such is the way of capitalism. It's better to animate a product that's still being released than a product that went on sale long ago, and therefore skipping ahead to the sequel makes more sense than making more of the original. Who cares about art? Money makes the world go round.
I hope they get to the zombie apocalypse in the anime, that's still the finest moment in the series.
Now that I have a slot freed up in my anime wishlist, I added Futari Ecchi in UQ Holder's stead. The three oav's made in 2014 were really splendid, and if they just did an entire season at that level of quality Futari Ecchi could be a great anime just like it's a great manga. Futari Ecchi is too sexual for a tv season, but there are oav seasons, like Maria-sama ga Miteru Season 3, so it's still a possibility animators should explore. The many fans of Futari Ecchi, one of the longest manga of all time, would surely thank them.