OK.. so I have kind of a different take on where difficulty post-asic will wind up....

I have no idea in hard numbers / actual terms... but in relative terms, it will wind up wherever it needs to be for the break-even running costs point to be around 10 cents per Kw/hr..   (this will of course vary based upon the USD/BTC exchange rate)

So.. if your electric costs more than 10 cents, don't even bother getting on the waiting list.. you'll never get your money back.

If you pay between 5 and 10 cents.. your break even (initial purchase + running costs) will be 1 to several years...   Up to your individual confidince in bitcoin if you wanna play.....

If you pay less than 5 cents.. Time to beg/borrow/mortgage-the-farm and buy as many ASICs as you can.  You will be in the select few who will still be able to mint money mining. 

If you happen to live in the arctic circle, and heat with electric.. well then you might wanna consider robbing a few banks....  Just buy the company outright.

And one last thought...  just like the gold rush, ultimately the ones who make the most money will be those that provide the picks & shovels (errr ASICs).. not the miners. 

Sigg