I thought I might throw a little confusion and hysteria into the fray.
According to HotGB and TotHW, there ARE dragons that control sources. And if
you look at the sheer domain power of the suspected Dragon in the Drachenward,
I think you might begin to suspect that dragons, as a race, may *freely* tap
any and all magical source holdings they get their claws into. And that is
what I did for them in my campaign.

I know that a couple of my players read this list, so I'll take this
opportunity to terrify them. Imagine what a dragon, with domain power of over
50+, could do with a massive Polymorph realm spell. ::evil chuckle::

Additionally, it is my belief that it was the dragons that were responsible
for the ancient ley lines. From time to time, it is known that dragons did
befriend elves. Perhaps they taught the elves some of the dragon magic, now
long forgotten. With this magic, and the dragons' permission, the elves could
tap the ancient ley lines.

I also will note that I read somewhere (I think in the article on Tarazin the
Grey) that dragons are *immune* to the bloodlines. IMC, I rule that the
dragons cannot gain bloodlines, nor are they affected by them. This doesn't
mean that your bloodmark would go away, but your death gaze might have reduced
or no effect upon a dragon.

Also, surely I'm not the only one who noticed the presence of the Dragon Isles
in the sea maps? Now that, in my mind, leaves open some *very* interesting
possibilities. ::less evil, more thoughtful chuckle::