Well, the dragon is never going to be powerful but it can certainly be useful.
For one, it can spot invisible creatures and warn its 'owner'. That's worth one feat right there.
It can also speak with animals 3/day. (a 2nd level spell-like ability)
If there's ever an object you need to recover that is protected by a powerful lightning field, or underwater, the dragon can go there with no problem.
It flies and it has super senses, so it can make a very good outdoors scout that'll warn you of ambushes in advance.
Whenever you meet monsters without missile weapons, it can fly overhead and use its breath. Its cone of repulsion has only a DC of 14, but some powerful monsters have bad reflex saves. Assuming you are a level 9 party and you meet 4 hill giants (a EL 11 encounter), if the dragon breathes repulsion gas on them, about half should fail their saves, so you might get to fight two groups of two (or even better, two, then one then the other).
It should be far from useless, if you use it well.
