Since its using cartridges there will be no backwards compatibility in terms of physical discs. Does this annoy anyone? 

Backwards compatibility was one of the reason i bought a WiiU actually,  since i never owned a wii i thought the possibility of playing two new libraries of games was awesome. 

That and the Switch runs on a different architecture.

There may be 3DS backwards compatibility. It uses cartridges, after all.

Its always sad when theres no BC.

i think the chance of backwards compatability is very small, I don't think there is a harddrive in the console but maybe you can attach one trough USB on the docking station so it would be nice to see NES-Snes etc classic games on backwards compatability I guess

Eh, I love backwards compatibility but I own all of the consoles anyway so no big deal. What is an issue is that Pokemon will be on 3DS and not NS. People aren't going to want to carry both around and Pokemon is bigger than anything NS has to offer.

I am buying the Switch to be able to play PS4 caliber games on the go. Say what you want, but the ability to swotch between TV and handheld is a huge deal for me.

There is a lot of potential for Nintendo to knock it out of the park with or without BC. However if they did 3DS BC, that would be HUGE.

From what we can tell from the teaser, the new cartridges are smaller than the 3DS ones, so I wouldn't count on physical BC.

What makes you think there won't be Pokemon on NS? March marks the death of 3DS support, everything will be NS only from now.

Not at all.