I doubt you could count bitcoin mining as gambling. The returns are just too consistent. Perhaps you could treat it like a commodity like a mineral mined from the ground.
I've been book keeping on the assumption that mined bitcoins are like inventory being created at a factory. That is it incurs expenses, but has no taxable value until it is converted into local legal tender. Of course I'll change if I receive different advice on how to go.
That's certainly an ambitious argument, personally I don't think the IRS will go for it, but you can give it a shot. I can see them claiming that if bitcoins are used as a currency, when you receive them, it's the same as receiving currency.
They definitely are not going to go for the idea they are mined as a mineral, unless bitcoin users are willing to spend big bucks lobbying them into those tax breaks, like the actual mining companies have.
I have a feeling we will find out soon whether it even matters, as bitcoin values either seem headed towards the stratosphere or back down to being worth pennies.
Oh - there are no tax breaks for mineral miners in my jurisdiction.