My opinion is that Battlestar Galactica was an okay series that suffered from an absolutly awful ending even if it did tie things up. It left me feeling very unsatisfied overall.
I've never been a big fan of direct prequels. It's one thing to set something so far in the past of a world that it has no bearing on the events of whatever the main series/product was, quite another to work backwards with continuity.
That said, I suppose if they are launching another prequel series, the fanbase must be that hot from the first one they did.
IMO if they are going to mess with the property, I think they should work on a sequel set after the evolution on the new world. Since we all know how this is supposed to work despite the high note, it would actually be kind of interesting if they used that audience knowlege of the "this has happened before, it will happen again" thing to have someone derail the entire process, break the cycle, and restore free will so to speak. Maybe having someone from the Galactica playing Hari Seldon (Asimov referance), using their understanding of the revelation to start a secret society to keep an eye out for this, or perhaps records designed to be triggered should similar events seem to be transpiring again. Maybe both in a true "First" and "Second" foundation style.
Of course then again I'd rather they took the money they are investing in this and would launch a new project. Enough with the trippy Cylon space angels already.