[mensetmanusman]

Has anyone predicted its size over the next 100 years?

[BetaDeltaAlpha]

New blocks are capped at 4096 bytes (plus some metadata), figure one every 10 minutes and there's your growth rate.

It's slower than the growth of storage/$$$

[radlad]

Of course if you're buying a 14" Macbook Pro, the upgrade to 2TB will cost you $400. Or $1,000 if you want 4TB (on top of the cost of upgrading the processor to the Max chip - necessary for that option.)