Hirai outlined details of Sony's recovery plan today at a news conference in Japan. Regarding the "Welcome Back" program, alluded to in "make-good" promises extended by Sony Computer Entertainment earlier this week, all PlayStation Network subscribers will get a month of PlayStation Plus premium service free; existing PlayStation Plus subscribers will get their terms extended a month, free. "Selected PlayStation entertainment content" will also be offered for free, on a region-by-region basis, as a welcome-back inducement. The content type was not specified, only that "it will be announced in each region soon."
Sony also did confirm there will be a new firmware update for the PS3, but surprisingly, not the PSP when PSN returns. Previously it had been speculated that this firmware update will force users to update their PSN password and other account information. Friends lists and trophies have been said to be fine, and will make the transition (I imagine there would be riots otherwise, but likely this data is kept on the PS3's hard disk and will simply sync to the "new" PSN).
Sony has not given an exact time frame for PSN's return, but they have said:
...SCE and SNEI plan to start a phased rollout by region of the services shortly.
...so it kind could happen any time now. Just depends on Sony's definition of "soon".