If you have an iPod connected and voice recognition catalog turned on then it takes quite a bit longer before you can control the iPod. Making sure the iPod isn't connected when you turn on the car and then connecting it will decrease the amount of time this process takes considerably.
This has nothing to do with how long the system takes to boot though, that's just a long time regardless of whether or not an iPod is connected.
Personally, the last thing I want to do is lug DVD's out to my car to watch a movie, so that wasn't a big deal for me. MSN Direct would be a bigger issue.