I'm sure the Virginia class boats are extremely capable, but the Navy is currently planning for a successor class, currently designated SSN(X). It will be quite a while before the first boat is commissioned: 2043?
https://en.wikipedia.org/wiki/SSN(X)-class_submarine
At this point any characteristics are both classified and speculative in open sources, but here's an illustration for what it's worth. One interesting speculation in the illustration is that the SSN(X) may be equipped with lightweight torpedoes in addition to the traditional heavyweight (Mk 48) fish.