As a member of both UXE and UI-SE, I can say that both sites are essentially dedicated to answering the question, “How do I get the best UX for my UI?” so merging the two sites makes a lot of sense to me.
Now should the name of the merged site emphasize the UX or the UI? I would also be in favor of renaming this site ux.stackexchange. In addition to representing the merging of UXE into UI-SE, I think it will clarify what this site stands for.
Occasionally UI-SE gets questions in UI development or implementation (e.g., jQuery plugin for auto-completing AND dropdown functionality?). Putting UX in the name may help preemptively redirect such questions to Stack Overflow. Not a big deal, since such questions are easily migrated, but it may help.
“UX” would make it clear that this site is open to questions requiring UX expertise beyond computer UI itself (e.g., packaging, retail space design, customer service, technical support). I’m not expecting many questions on these topics (I can’t find any over at UXE), but I think it’s good to include them.
Regarding UXE not having a meta (among all the technical issues related to merging), you can probably simply consider all questions tagged UXExchange to be metaquestions.
Another thought is that if the merge goes through, I think it would be nice to provide some personal recognition to UXE founder Matt Goddard for his efforts in creating a UX community of experts, and demonstrating the feasibility of a UX/UI-only SE-type site. I’m not sure what he’d be interested in, but making him an “instant moderator” of the new ux.stackexchange may be a start.