1) Digital Foundry / Eurogamer claims in an article that 4.5 GB is available for development at launch, with 512 MB / 1 GB as flexible memory
2) Various, unbanned GAF insiders have said "That article is incorrect"
3) Thuway, Famousmortimer, BruceLeeRoy, and Verendus (all unbanned) have all heard "The memory situation on PS4 is ideal and has exceeded expectations in every way." That should mean that games at launch won't be affected by any kind of restrictions in place
4) Thuway stated that some games currently in development are using 6 GB of RAM, but also implied some form of RAM restrictions at launch is not completely out of the equation
5) Kagari (has connections to Square-Enix) also agreed with the 6 GB claim
6) VBlank Entertainment (Retro City Rampage) has denied that Sony is reserving 3.5 GB of RAM for the OS
7) NOTHING is confirmed until either Sony states something or launch RAM allocations are revealed in some way