The new series will be called XXXHOLiC ◆ Rei (XXXHOLiC ◆ 戻 < レイ >) and will be published in Young Magazine. The kanji for 戻 roughly means "return".
This will coincide with the release of the XXXHOLiC artbook, the TV Drama and also the series' 10th Anniversary.
All of this makes a lot of sense, if you ask me. There couldn't be a better time, strategic-wise, to resume the series. I would presume that Kodansha and CLAMP already knew that there would be a live action adaptation and decided to put the series on hiatus in order to wait for it. I'd say that everything was planned from the start.
So CLAMP is back to weekly magazines, and back to 3 works simultaneously. Very nice!
In other news, we now finally have the release dates for GATE 7 #4 and Drug & Drop #1. It will be a simultaneous release on February 4. Drug & Drop #1 will cost 588 yens.