Good news everyone! Looks like the folks over at Bethesda have listened to our cries! Fallout 4 will let you continue playing even after you finish the main story, and there is no level cap!
Previous entries in the Fallout series have had issues with their endings. Fallout 3 for example had players enter into a scenario that forced them to STOP playing. If you saved and reloaded, the doors behind you were locked. If you wanted to muff around anymore, then you had to start all over OR not even finish the game.
The removal of a level cap seems odd though, it will be interesting to see how ridiculous players can get their stats up to.
Fallout 4 hits stores November 10th.