There's a positive and a negative in this news.
The positive is that the community appeal will increase drastically to the unknowns lurking. There are other possible positives such as the people who have been addicted to the Starbucks forum once again becoming active in more useful areas of the RunUO Forums. However it's also likely that they could just quit, or migrate to SoRaged? (But, considering the ones to do this are likely the least -currently- least contributing members, I guess it's a sufferable loss.)
The negative, as was partially stated above, is that the activity of the forum in general will seem to decline, for at least awhile. At least, that's what I'd expect. Hopefully it'll pick up quickly with better discussions than "check out this cool ___noun___" (40 pages). I hope for such.
And lastly, a possible forum suggestion for the future, that may or may not have been introduced or thought of in another time and place... RunUO Re-engineering Discussion! I know above you said getting back to RunUO and UO discussions is the whole idea of retiring Starbucks, but maybe a possibility after the community picks up or something. The general idea is that the source code could be nitpicked and disected, publicly and discussed for use in other peoples work. It'd also provide a means for people serious about reworking parts of RunUO a liason of communication directly to the creators themselves for help, or other really experienced coders. Of course I completely understand if the idea is neglected, as RunUO's primary function has always been a server software for the emulation of OSI RunUO (for the most part). Just a thought. Also, if another part of this forum is already set aside for such discussions as this, then I must've been overlooking that. Lastly, if the reason were for any legal purposes (Public discussion of WoW RunUO mod remakes or whatever) it'd also be a problem, so again, understandable!
And lastly, I really really won't miss most of Starbucks. :|