If its the end of the world then doesn't matter how much money I've got or what in it'll be worthless and a shotgun might useful. If its just a catstrophe then I'll want to go in and buy some shares at the knock down prices which will be around then and look forward to an enhanced retirment. Most likely is that we'll muddle through and I'll still have my divdends etc to keep me warm. As life isn't certain I've got shares with different providers in case someone in financial services tries to run of with my savings, but other than that I plan to have as little to to do with IFA's, pension companies and their high fees etc as possible.
Unfortunately the biggest real risk I see is that politicians will promise the earth to get elected and then use other people money i.e. the retired and savers, to pay for it. The technique which has been used is to create a bit of inflation so effectively the tax take increases, more people fall in to 40% tax bracket, So whatever you do has to take account of inflation. The only thing which does that long term is shares.