In case you've missed the news, major Fallout 4 details are being shown at QuakeCon today! The Nukapedia team would like to feature some highlights here (to be updated as we go). We welcome plenty of discussion on this blog post. Special thanks to Sarkhan the Sojourner for compiling the notes.
5. It is confirmed that Preston Garvey may serve as a possible permanent companion, should he be accepted by the player.
7. Including the aforementioned possible companions, there are "around a dozen available companions" in total.
8. The Pip-Boy has been expanded to show more information than in previous games.
9. Several items have been confirmed: nukes, gas masks, books, and med-packs.
10. The PC may become over-encumbered. The PC is killed by a raider since he could not escape.
11. 1 perk per level (unlike in Fallout: New Vegas)
12. Bloody Mess is back!
14. The PC finds a Super-Duper Mart and sends the dog to search it. The player then proceeds to hack a computer.
15. Another confirmed location - a Corvega power plant.
16. A melee weapon is being used. It is metal with edges of razors.
18. The Fat Man is back!
19. An enormous "behemoth" mutant is shown. The PC kills it using the Fat Man (with VATS).