Well, I know it's not much, but I figured I should say it: I think the fact we're getting a new Mario & Luigi kinda helps Golden Sun, even if only a little. Obviously, it shows that Nintendo is willing to work with a different company for a game should the usual one be unavailable (like Camelot being busy, or AlphaDream being... dead), and if certain insiders are to be believed, there IS interest at Nintendo for a new Golden Sun. Heck, I wouldn't be surprised if the reason we're getting a new Mario & Luigi is BECAUSE of such interest, given several former AlphaDream members apparently joined Nintendo after they went under. I know a lot of the time there's an ulterior motive when it comes to reviving a dead IP, but sometimes? It really is as simple as "we want to make a new game in this series".
Sorry if this is rambley, just something that's been on my mind lately.