In other worlds, I have sometimes seen the idea that faith and the magic of prayer is simply a means for the priests to channel and focus magic, much like bat guano and incantations are for the wizard. That is, magic is not inherently divine, even as spoken by priests, but a force natural to the world, channeled through different means.
If we run with this idea for a moment, one might consider both the gods and the dragons products of the same underlying magic force, something built into the world at its creation. In the GW case, we have a magical dimension (The Mists) that may be the original wellspring of this force, and which imparts some measure of it into every other world it touches. Both gods and dragons are beings, either ascended once-living ones, or beings born/created from particular powerful interactions with the magic force (the magical equivalent of a solar flare touching at a specific point between The Mists and Tyria).
The difference between a Dragon and a God then could be considered the difference between wild and tamed, between instinct and intelligence. Dragons are an older form of magic, more primal and untamed, and these creatures were born or ascended with this aspect. This fits with the notion that they are more akin to forces of nature than some refined aspect of philosophy. A God is a later construct, something born out of a more intelligent understanding of the magic force. They are, I think, more likely to be ascended once-living creatures than dragons, born of a willful, even if unintended, manipulation of great magic. The emergence of organized wizardry may even have slowly changed the manner in which the magic force impacts Tyria; many generations of using controlled magic made it easier for magic to enter the world using these channels, instead of wildly brute-forcing its way in whereever it may. Magic became, not tamed, but more likely to have an intelligent and philosophical aspect, and in that sense no new elder dragon could be made today, but new gods may occasionally arise (point in case, Kormir). This strengthened the Gods and their influence. Still, the wilder, older magic persists in places.
The gods and the dragons are thus, in essence, equally powerful. Yet at the same time, their natures are at odds, and with the elder dragons once again seeing their power increasing, their influence surpresses the more refined and controlled influence of the gods. The philosofical influence of Grenth, Death and Ice, is diminished in favor of the more wild influence of the dragon of ice, Jormag. Melandru, he of Nature and Earth, may buckle under the pressure excerted by Zhaitans alternative influence on just how nature and earth should behave in Orr. Balthazar, god of Fire and War, may be influenced by the more unrefined influence of Destruction wrought by Primordus himself.
I don't think it's a clearcut case of 1-to-1 overlap, if we accept this premise though. Zhaitan shows some influence over Death (as evidenced by his power to raise them as undead), whereas Jormag clearly holds the power of Ice, both of which fall under Grenths portfolio among the gods. Still, this also fits with the dragons being proto-gods, more untamed expressions of basically the same force interacting with the worlds and its inhabitants in different manners.
It also ties back to the original idea: a monk is using magic as channeled through the gods and their expressions of it. An elementalist taps more directly into the underlying magic of the world. Both could do some of the same, f.inst heal, but by applying difference concepts: the grace of the gods vs. the lifegiving properties of water. And for a kicker: I wonder what a worshipper of the Elder dragons may pull out of their hat! Tyrias first Wild Mage perhaps?
Three minutes thought would suffice to find this out;
but thought is irksome and three minutes is a long time.
-- A.E. Houseman