I have this setup and a canon SX150 and I agree wholeheartedly. I also have the glitter eneloops. It can be very hard to find a camera that uses AA batteries though now but I am happy with the one I have so I don't see myself needing another for quite some time. I have Duracell rechargables which some of them are just rebranded eneloops and they work just as well as eneloops. This setup is also completely necessary for the Wii controllers.
I am not sure why you would want a lithium battery in a camera, yes it makes it slightly heavier but it's also more expensive to buy another when the first one dies. You will probably be using the camera past the expected lifespan of the battery too.
My usage pattern with cameras doesn't work well with lithium either. My camera needs to be ready when I am, and eneloops work perfect for that since they are always charged and ready even when sitting in the camera. If I had a camera with lithium that discharged every 2 weeks I would be beyond annoyed with it since every time I want to take a picture the battery would be discharged and I would have to wait 3 hours for it to charge.
As for the Wii U that is another problem. Since the battery life is so short it has to be charged more often. This means more wear on the battery, which means you will need to buy another battery sooner. Most people will be keeping their Wii U more than the expected 2-3 years of the battery in the gamepad.
Something must be up with these new lithium batteries also. I remember having a DS Lite and the battery would last forever. You could leave it for 6 months, come back to it and still play for a few hours. Now the batteries discharge in a week or 2 and you can't play without plugging things in. I am not sure but battery technology seems to be getting worse, more expensive and less consumer friendly.