Basic math shows how overpriced the shares are: there are ~10million more bitcoins left to be mined over the next century or so. Even if ASICMiner were able to maintain 20% of the total network hashrate throughout that period (breathtakingly unlikely), they'd only mine 2million BTC. Split between the 400,000 shares that creates an upper limit of 5BTC/share.
You did forget the hardware sales
You forgot 2 things:
1) If a company is selling shovels to those looking for gold. Can the company make more than all the gold that exists in the world? Obviously YES. AsicMiner is selling shovels. I saw someone try and estimate the amount of hashing by asicminer hardware (sales + it's own) - i think it was more like 30% of total network speed.
2) Transaction fees. When bitcoin takes off we should see transaction fees drastically increase, thus the about 'mined' is infinite.
This is correct. If Bitcoin is to succeed, then AM will likely be around for a long time. If there is mass adoption of Bitcoin, block rewards could be higher than they are now.
Does anyone else find it interesting that the share price of ASICMINER has seemed to move inversely proportional to the price of BTC? Perhaps this is do to the recent string of IPOs and people looking to make a 'quick buck'. IMO, ASICMINER is a leveraged bet on the success of BTC and if BTC is successful then ASICMINER is vastly undervalued at current levels.