I'm aware of the strength of AES-256.
However just remember the days when 56-bit encryption was seen as uncrackable and impossible with any amount of computing power... Today computers crack that in 30 seconds.
Who is to say AES-256 is going to remain computationally unfeasible in the future? At least AES-512 is overkill and overkill is what you want when it comes to security and privacy.
The weaklink in PGP is the RSA not the AES (technically) I think it would be wise for PGP to incorporate up to 16,384 BIT RSA keys just to be future proof for a long time coming.
I know a LOT of organizations are still using 2048 bit keys but I wouldnt trust a 2048 bit key.
I belive 1024bit keys have been cracked by the NSA I'm sure 2048 is safe for time being.
I want to feel safe for a lengthy future 16,384 bit would provide that confidence due to the insane computing power required to crack it.
PGP seems slow to adapt to change where as other products tend to stay on edge I personally like PGP the best and I do hope they fix DropBox for consumer not just Enterprise customers (which they did) and add higher RSA keys in.
And still nobody has given me a fix for PGP and DropBox..... Still waiting on that.... Yup...