I know lots of people have posted threads about getting kobolds as a race so heres mine. ;-)
In the Eberron setting there are three subtypes of kobolds the iredar, the irvhir, and the isvern.
The first two iredar and irvhir and common and only distinguished by their scent and spell choices. The third subtype the isvern is a rare and winged subtype said to be descended from Siberys (in fact each race is said to be descended from a different of the big three dragons in the settings mythos).
So the iredar or ones of earth are the ones we help in challenges, they aren't evil just scaly.
The Irvhir or ones below are the ones we slaughter wholesale in quests and they are evil.
The third the Isvern or ones above are the type we should get as a playable race. The big advantage to this it that while the first two are supposed to have basic kobold stats the third actually have no published stats meaning the devs wouldn't be constrained with the awful baseline statistics of standard kobolds. Also since they are are supposed to be rare enough they are considered a legend introducing them on this newly explored continent as a possible group of heroic adventurers makes sense.
Oh and for pnp players I'm not just homebrewing this stuff races of dragon p54 :-D