No, I see "mining" as taxed like any other business where the owner has skin in the game. The miner will not be able to take out his own labor, only expenses for equipment, salaries, repairs, electrical costs, and any other associated costs for producing coins.
Where I see a problem is as you observed: "Bitcoins are neither a currency nor a property". I suggest they are a little of both. IMO, they should be treated like a currency by those who acquire them for convenience and use them for purchases while treating as an asset for those who trade or mine them.
I'm not sure how you keep the two separated. It is indeed a problem looking for a solution.
Properties are “NOT FUNGIBLE”
Bitcoins are !!!!!!
Equities have a limited fungibility where as a currency does not.
Fungibility:
Fungibility is the property of a good or a commodity whose individual units are capable of mutual substitution. For example, since one ounce of gold is equivalent to any other ounce of gold, gold is fungible. Other fungible commodities include sweet crude oil, company shares, bonds, precious metals, currencies. Fungibility refers only to the equivalence of each unit of a commodity with other units of the same commodity. Fungibility does not relate to the exchange of one commodity for another different commodity.
http://en.wikipedia.org/wiki/Fungibility
The IRS ruling, from what I understand, is an attempt to deem Bitcoins as NOT being fully fungible, even though they are, and classify them as a hybrid.
In the late 1990’s there was an effort to create a new currency based on “airline miles”, miles/credits that could be accumulated and traded for cash etc...