Yes, Linux Libertine is very close to Calluna (especially the "C" glyph).
Additional benefit of this font set is it includes a set of keyboard glyphs which will be very useful for the tutorials.
Font homepage:
If we would like to keep the original font appearance, I don't think this needs a community vote.
This is also going in my personal 50 essential open fonts list, so thanks Gez, for the tip! :)
The only /slight/ issue is that the kerning needs a bit of work.
Fortunately, since it's an open font, we can fix it. :)
All in favour of making Linux Libertine the official Inkscape font in place of the proprietary Calluna Regular?
So far:
3 votes - Yes
-C