To date, I think they can formulate about the first 10 digits, effectively with a standard computer, of any sha2-cypher. Beyond that, you have to just use brute-force, and "hope" for a solution, or a collision.
But as for ASICs... all they will do is squash out anyone with lower hash-rates, just as the GPU miners did to CPU miners. There is still only x-number of coins made per day, so the market will go from having several thousands of miners, down to about a few hundred, and then down to about three. The last three will be the ones who actually manufacture the ASICs... and I doubt that will be the ASIC producers we see here today. (BFL, AVALON, ASIC-Miner)... but it could be them... in the end, fighting over the same devalued coins they caused to devalue. (Using our money to make them what they are today. While they leave us behind.)
Funny thing is... once they all have 50THs each... that will make 49THs more than is required to "process" the few actual transactions that are trying to get in to the list, to be processed... (See, that will be three individual "processing gateways/servers", because there will be no more of the thousands of "GPU servers", running to collect the orders. Thus, even if the price does not fall, few will actually be able to get an actual transaction done. Unless they scatter the machines all across the world, and buy lots of internet connections, and then they will be in massive debit.)
Once the price hits $1000 per BTC... All the GPU's will have moved-on, and all the mini-ASICs below 1.5THs will be gone too. I am guessing, by income-tax time... next year. (It was already up to about 1/4 of that price, and people paid it...)
Then they will be forced to do a pump-and-dump of BTC into every other still-thriving alt-coin on the market. (Where all the GPUs will be mining... and they will try to rape us again... It will not work. We will just make a new system, that avoids all this horrible loss, and has a little more stability. Then they can come back and use the machines to HELP us instead of RAPE us.)
ASIC = AIDS
(Just like GPU was AIDS to CPU's)
But AMD didn't turn around and build mining rigs for themselves, and then stop selling us video cards... They made us more video cards! ASIC manufactures are building 1000 for them, and 1 for us... thus, selling us back 0.1% of the market, that we helped them build, with our cash.