Personally I want to see the Dark Age come back to life. We were left with a major turning point in the series and then, well, nothing.
As far as the end of the Star League it would be really nice if Randell Bills or someone else would finish the Exodis story of Kerensky and the SLDF forces. I would renew my subscription to read those. Also, the build up to the fall of the Second Star League was simply dropped. There seems to be a pattern here of starting story lines and dropping them before they get going.
Anyway, if I had a choice I would say go with Dark Age. Let's get this war moving forward again.