Well I have to tell you that most people think DL is more magical than the MK, if those are the only 2 parks you compare to each other. DL is more compact, very intimate and charming IMO. Around every corner you will find something. There are absolutely no wasted spaces. Like Hydroguy said, there are more rides in DL than in the MK. Most people also agree that the detail and attention given to Fantasyland and Toontown are way better. New Orleans Square is wonderful too.
Since the park is smaller, it is not such a long walk to get around, which is nice with small children. But that can lead to crowded pathways and such when it is busy. Strollers are a challenge then.
What it doesn't have, is the exclusiveness of WDW, which is what alot of WDW vets like. But if you stay onsite, you never have to leave the magic. You walk to the parks through DTD which is connected to everything. If you want to spend some bucks, stay at the Grand Californian, which has its own entrance into California Adventures. Many people stay offsite too, which is a great perk to save money. If you do that, I would still try and stay somewhere close enough to walk to the parks. There are many hotels to choose from within walking distance. No need for busses.
Park hopping is a breeze.
If you walk from the entrance of DL to the entrance of DCA, it takes about 2 minutes. That's how easy it is to park hop.
There are quite a few attractions good for your little ones too at DCA. Bugsland, Redwood Creek Challenge to name a couple. And don't forget the most talked about show to come to any parks in a long time.
The "World of Color!"
If you want to see some other parts of California, this would be the perfect excuse to come. There is something called a city pass, which gives you passes to DL, the San Diego Zoo and something else.?
There are a lot of reasons to give DL a try. When folks actually give it a try, they are pleasantly surprised.
Oh and don't tell your wife how small Sleeping Beauty's Castle is. That just might push her over the edge to say "no." Then you will need that divorce!

