Will smartphone cameras reach or finally exceed DSLRs?

Not unless we find some new materials to replace silica glass. Surface marring from simply holding the camera in your pocket will reduce useful performance well below 10MP. Getting a lens to resolve 100MP is hard; getting one 3mm deep to do it is almost impossible.

Based on the existence of usable crude forbears to modern DSLRs about 10 years before modern cameras hit the market, I suspect we're still going to be looking at much the same sort of camera. Multi-sensor devices are also limited to primes at present.

How about the highest end of digital imaging, like MF? We have 100MP, how high will we go?

For MF? Much higher. There's a reason people still own large format film cameras.

Will sensors keep getting bigger, until we have real large format sensors?

We already do - though they're not really usable for anything but test pictures. It's possible to get MF glass above the 100MP mark, and 6x7 sensors could theoretically do much more than that. I question the utility of gigapixel cameras - it's not like we're about to start printing more than 300DPI, as we'd never tell the difference.

And how about professionals? Will weddings just be a swarm of smartphone pics posted to social media in real time?

I just shot a wedding. I could've done it with the 3-year-old DSLR the MWAC brought along without massive inconvenience - it's the lighting and practice that makes the big difference.

Just because pencils are cheap doesn't mean we're all going to be Hemingway.

24 years?

We'll just download images directly from our optic nerve.