We have considered going the camper route. We would also like to spend a couple days at a nice resort with some kind of "kids activities/club" so she can be around other kids and hubby and I can have some alone time...

Melbourne to Sydney is only 872 kilometers, and not realy worthy of a ten day trip, You don't say when you are travelling, but right now the North of Victoria is ablaze with bush fires, with a lot of the nice coastal towns under threat, so not sure what will be there when you travel,
If it is summer towns like Merimbula, Bega and Pambula on the southern NSW Coast are good for family holidays, but they don't have kids clubs.In winter it will be cold all the way.

Depends on what type of activities you re wanting to see. I am not sure where you are from but the area from Melb to Sydney is rural with lots of small towns and from recollection no touristy resorts in between. However there are some lovely small towns along the way that hold lots of historical interest and great scenery. Would depend on what time of the year - very hot at present and North East Vic is full of smoke with fires. If you are looking for resorts would try Qld or northern NSW but again the trip between the cities is great but just depends on what your interests are.

clarification:
Travelling Jan 13-22. We live in Hawaii so we are interested in maybe a couple of beach days, but not too many.

I hate to put a dampner of your plans but I would seriously reconsider this considering that you will be travelling in January.

As several others have mentioned, there are a lot of large, very large, bushfires around at the moment. A number of towns are under threat and a number of major roads cut with "no go" zones. Fire authorities are seriously talking about letting the fires burn to the sea. Last year it took 6-7 weeks for some fires to burn themselves out.

What I am concerned about is that this is only the beginning of our bushfire season. January is extremely hot and there is a huge potential for more fires all through January (and beyond). This is expected to be the worst bushfire season in 30 odd years.

As you will be travelling with a 2 year old, I really wouldn't like to chance it. It would be horrendous if you got caught up in this. I'm not suggesting that you are all about to die but road closures, evactuations, burnt out countryside etc would effectively ruin your precious holidays and your little one might find the whole thing rather scary and overwhelming - not to mention that you would be terried for her safety.

The trip from Sydney to Melbourne can be lovely - just not at the moment. Perhaps you would be better considering Queensland. There would also be a much bigger choice in terms of places which offer "kids clubs" there. As you are from Hawaii you probably don't want to spend all the time on the beach, but the hinterland of Queensland (a bit away from the coast) is lovely too.