That sounds good to me. My reference to swapping cards as dangerous is because it is the time I find people most likely to do something bad - drop the card in a puddle, stick the card someplace where it will get lost, etc. It goes from being safe and cozy in the camera back out into the wild.
It's a safety tradeoff. Put too many pictures on one card and you may lose them all in the unlikely event that the entire card fails. Break things up by changing cards and you increase the risk of messing up or losing one of the cards. The appropriate balance probably varies from person to person based on their handling of memory cards and skills at recovering photos from corrupt cards.
Actually, this is already possible. Several cameras, like the Canon 1D and 1Ds series and the Nikon D3 have dual memory card slots and can be used to write to two cards at once. Devices like the Epson P-5000 can be used to download pictures directly from the camera.
I stick two 16 gig cards in my camera. I typically shoot 500 to 1,000 shots in a day, which easily fits onto one of the cards. The camera automatically copies each photo onto both cards. At the end of the day, I transfer them to my laptop and burn a DVD. I take the laptop and the DVDs home in separate bags.
Nothing wrong. We just have different approaches. I think the important thing is to be conscious of the different risks and take reasonable steps to mitigate them.