The value of ASICMiner:

The value of ASICMiner depends on the total profit it can generate. Let's do some math.
Total bitcoins to be mined: 9,600k
ASICMiner takes 20% of total hash power. This will generate 1,920k.
Assuming hardware sale income is 30% of mining profit, so this part is 576k.
(1920k+576k)/400k=6.24B/share
This is the total profit one can expect for 1 share of ASICMiner in the next 20 years.

value of 1 share of ASICMiner = share price + dividend = 6.24

How will the 6.24B be distributed between share price and dividend? Well, this depends on the investors' emotion and their view of the risk of future income. The gap between 6.24 and share price is risk compensation.
IMO, the share price will fluctuate between 3.x and 4.x in the future. 5+ price is too risky.

My 2 Satoshi.