It will be politically impossible to make serious changes in absence of a major crisis. Personally, I believe the very internal economic logic of the GSE's could produce such a crisis. A Fannie Mae crisis prompted by deflation or derivatives trading would simulataneously take out the bond, stock and real estate markets, for example.
The problem of money is a tricky one. I'm not a gold bug but I have been pleased at the recent emergence of electronic gold. The fiat system is lunacy. The government is the largest and most irresponsible debtor in the room, so their bias will always be towards debasing the currency. Until it is impossible, that is. Then you've really got your tit caught in the wringer.
My best guess is that a deflationary environment will be the endgame for Keynesian economics. Afterwards, I'd like to see corporate taxes (in reality a regressive consumer tax), capital gain, and income taxes abolished. A National Sales tax should suffice. Restoring the nation to a Constitutional Republic from its current status as a Socialist Democracy would also be nice.
As far as currency is concerned? Since capital gains taxes would no longer punish you for not participating in the inflation, you could use any thing you please, a tri-metalic currency or one backed by a basket of equities.