This wouldnt even be able to compare to 1930s as if you take a look at DJ in 1930s, it was down by more than 90%, it dropped to around 2000 right now it is not even 25% as bad as 1930s...
But yes, it is still bad...comparable to 1987 almost. but think about it this way, after GS and MS transform to deposit taking institutions, financial market would be going up again(well, not in next couple yrs, but eventually would).
plus the rest of the world are helping US, it is not like US and England are by themselves alone. China, even tho it is not one of the G7, has lent US more than couple trillion dollars as of today. And China did it without even thinking about the consequences.......the US FX rate and all the bad debt + the begining of the recession would make China lose all its lending. Japan, Sweden have been helping out London to stablize its situation even tho japanese banking industry got hit as bad as everybody else.