Everyone seems to be getting pretty wound up about the slide pad cradle for 3DS.  Maybe I have bigger problems, but it does not bother me.  Here's what I think:

1. Its ugly, I won't say it isn't, but I actually don't take my 3DS on the road to play (I drive to work, no time to play portable games) that much I use it on Sunday afternoons at home and before bed.  I take it out to street pass and maybe I will have time for field runners. Thus I can leave the cradle at home keep the looks elegant on the road and not give a shit at home.
2. It makes the machine bigger in my hands.  The 3DS feels small in my hands this looks like it will make it more comfortable.
3. Added costs - the thing will be offered as a pack in for any games that need it, don't want those games you're good.
4. It gives the 3DS the same number of inputs as the Wii U controller, thus it will be a viable second input.  You won't be able to stream full games over to it, but because Pokemon Battle Revolution proved the DS could be used as an input for a Wii game the 3DS will be perfect for second and 3rd player.
5. Anyone who has not bought in already can just get the inevitable all in one redesign.
6. It is better than shoehorning dual analogue controls onto the existing hardware and adds more gameplay possibilities i.e. FPS, Monster Hunter