how many people really use the cradle ?

I use the cradle all the time

All the time. Sometimes I've even PLAYED my 3DS while it was in the cradle.

I put my 3DS in the cradle every night when I go to bed. I love that thing, and was disappointed that they weren't including one with the XL. If I end up getting the hardware, I'll definitely pick up one of these to go with it.

I also use the cradle all the time. I sticked it to my desk.

Yup, since launch.  Actually, I'm kinda sad that the XL doesn't come with a cradle.  Basically, it comes down to charging your 3DS with one deft movement of one hand, versus picking up the charge plug, which invariable has fallen to the floor behind your desk, finding that little spot on the 3ds to plug it in, etc..

As soon Nintendo decides to sell one, I'll probably buy it. 

Reread the story. ^_~

I also use the cradle all the time. I hope they sell it in stores so I don't have to order one online

Yikes!  I skimmed too fast.  19 bucks?  Eeh...some 3rd party will have to make one down the line, they must!

Never used mine. Took it out of the box and put it away, never saw the point to it.