Considering it's more or less an in-house show I'd say there's a good chance of renewal, though Sci-Fi Channel's made weirder decisions before. Sales of dvds and other merchandise can be helpful, esp. in BSG's case (see below).
Farscape, for example, was split between at least three unconnected companies, while BSG is almost all if not all Sci-Fi Channel/NBC-Universal. Which is also likely why the mini-series aired on NBC before the series US premiere.
Ratings for the US premiere (link), significantly higher than the norm for the channel. Now I expect the numbers to drop some and stabalize but that's a good start.
2nd Season's already being mapped out (link). Granted that's just good SOP but it's a good sign all around, esp. that Sci-Fi Channel is bothering to report it.
Trek Today article comparing ratings between BSG and Enterprise (link). Farscape was expensive as well but with BSG there are fewer slices this time around. If nothing else it will at least run as long as the original show did. ^_^
I've heard there are some suitably useful ones already. I doubt you'll ever see official ones. Far more likely to see toys and possibly some official model kits. I'm sure there are garage kits already out.
Finally, Ron Moore has a blog here:
http://blog.scifi.com/battlestar/
with some interesting answers. Worth a look.
[EDIT]General tweaking, added last link[/EDIT]
