We just got back from a DLR trip - just DH and I. We have been to WDW as a family 3 times now and have a fourth trip planned later this year. It is true that DL is smaller than WDW (I cannot get over how tiny Sleeping Beauty's Castle is!) but as far as Disney experience goes, they are both superb. Granted, we stayed at the Grand Californian which was an amazing experience and not something we can afford to do in WDW (we stay in the mods at WDW), so that may have added an extra element of magic that might be lacking by staying someplace else. But we found DL to be just as magical as WDW.
We are trying to decide when to take the kids to DL - next year, or the year after? Cars Land is opening up in 2012! Plus, the World of Color show in California Adventure is debuting in May of this year (I think). It is supposed to be Disney's most amazing and ambitious show ever.
The nice thing about DL is that you don't have to stay an entire week - 4 days is enough time to see everything at least once and all of your favorites multiple times. That may change when all the new attractions and shows come online during the next two years.
And, btw, the Electrical Parade is coming to WDW this summer. I have read rumors that it might be there for a while, as in possibly 2 years or so.
You don't need a car if you will only be going to the DLR. We took SuperShuttle from LAX (kind of expensive - $60 r/t pp) but we did not need a car once we got there.
You can easily park hop between DL and CA - it really is a 3 minute walk with no lines for security because you go through security prior to entering the Esplanade (the area between the two park entrances). You can even hold Fast Passes for both parks at the same time. DTD is right there off of the Esplanade with lots of dining and shopping options, although it is not the same size as DTD in WDW. The World of
Disney Store is the second largest in the world and has a large selection of Disney items.
The Disneyland boards here were a huge help in planning - I highly recommend them.
ETA - The Aladdin Show was ABSOLUTELY AMAZING. I am so happy we were able to see it before it goes dark.