Kadokawa added in their official website the cover of Kobato. #2:

Very pretty, isn’t it? I like it better than the 1st one.

I think we can assume that the tankoubon cover will most likely feature illustrations that appeared for the first time in a Newtype cover.

Kobato. #2 will be released on April 26.

EDIT: And since we are in the subject, su_chan has found a scan of this month’s Kobato. News!!, published in Newtype magazine, where we can see a preview of the CLAMP in 3-D LAND 6th Series package. You can check it in this post.