For US Tax purposes, is Bitcoin mining more like property, "work to solve a puzzle" or "winning a lottery"? From a taxation perspective, I think it's important to clarify if running a Bitcoin mining operation is more like property exchange, labor to solve a puzzle, vs winning a lottery that runs every 10 minutes.

I'm looking from someone to answer who is familiar with accounting rules regarding lotteries, gambling, and similar operations.  As it stands, lottery earnings are taxed at enormous rates.  (50%)  

Although I'm interested in US based operations, anyone with experience in other countries would be of interest as well.
In the USA, Bitcoin earnings are treated like property.  The full announcement is here:

Virtual Currency Is Treated as Property for U.S. Federal Tax Purposes; General Rules for Property Transactions Apply IR-2014-36,
March. 25, 2014 WASHINGTON —
The Internal Revenue Service today issued
a notice providing answers to frequently asked questions (FAQs) on
virtual currency, such as bitcoin. These FAQs provide basic
information on the U.S. federal tax implications of transactions in,
or transactions that use, virtual currency.
In some environments,
virtual currency operates like “real” currency -- i.e., the coin and
paper money of the United States or of any other country that is
designated as legal tender, circulates, and is customarily used and
accepted as a medium of exchange in the country of issuance -- but it
does not have legal tender status in any jurisdiction.
The notice
provides that virtual currency is treated as property for U.S. federal
tax purposes.  General tax principles that apply to property
transactions apply to transactions using virtual currency.  Among
other things, this means that:

Wages paid to employees using virtual currency are taxable to the employee, must be reported by an employer  on a Form W-2, and are subject to federal income tax withholding and
payroll taxes.

Payments using virtual currency made to independent contractors and other service providers are taxable and
self-employment tax rules generally apply.  Normally, payers must
issue Form 1099.

The character of gain or loss from the sale or
exchange of virtual currency depends on whether the virtual currency
is a capital asset in the hands of the taxpayer.

A payment made using
virtual currency is subject to information reporting to the same
extent as any other payment made in property.
Further details,
including a set of 16 questions and answers, are in Notice 2014-21,
posted today on IRS.gov.