Depending on your graphics card, a few dollars a week sounds about right. A mid-range graphics card (eg: a 2GB 6970, $300) has a MH/s of about 400, as far as I know the top range consumer graphics cards (about $1000) top out at around 1200MH/s, which is 1/4th of what the Jalapeno has. A 6970 would probably generate about $8/week at present, but the power costs will dwarf that so it's not really worth it, unless you're not paying the power bill.

The major problem is right now mining profitability is dropping fast and is going to drop even faster as all these custom built miners ship, you might be able to make a few dollars a week at the moment with your graphics card but once all these custom built miners start to ship (and there's tens of thousands of pre-orders) it'll become pennies. You've missed the boat on mining profitability with consumer hardware and anyone looking at custom built miners is going to be losing money too unless the value of Bitcoin sky rockets.

Most GPU miners have moved from bitcoin to litecoin or feathercoin as they use scrypt hashing instead of SHA256 so are resistant to ASIC hardware. Mining these currencies usually offer an extra 30-50% over mining bitcoin directly and can be sold for bitcoin or USD on various exchanges.

As an example for a $300 ATI 7950 card that generates ~600kH/s scrypt you will generate $1.33 per day in litecoins vs ~450MH/s with SHA256 which currently generates $1.01 per day in bitcoin.

With the onslaught of ASIC hardware coming though it's not clear what's going to happen with GPU mining. As more people move to the other currencies they will become less profitable to mine and could get to the point where they cost more in electricity than they generate in profit. Definitely bitcoin mining will be at that point by the end of the year for people without ASIC hardware.

Its in the article, but bitcoin mining is a race to the bottom. You are commiting a major fallacy if you extrapolate current rates.

CPU mining is pretty much pointless now. And unless you're not paying for power GPU mining is pretty much a wash. Assuming an ATI 5870 uses 200W, and can do 400MH/s (which looking online seems about correct), you can expect to generate about .01 BTC/day, which is about $1 at current rates. You'd be looking at profitability if your marginal power costs are less than $0.20/kWh. And that's not factoring in the cost of the graphics card.

For comparison, 2 USB asic miner erupters will hash at about 650MH/s, and use about 3W.

So in short, if you already have a fast graphics card and don't have to pay for power, it might be worth mining.

Probably less than you would spend in energy.

https://en.bitcoin.it/wiki/Mining_hardware_comparison

http://www.bitcoinx.com/profit/

I was mining with a medium-low grade GPU for about 6 weeks. I ended up with 0.3 BTC which is about $30 right now. If you had a $250 Radeon you could probably have done better at the time, but this was just at the beginning of the ASIC invasion so it's probably harder now.

Based on a ATI Radeon 5870, which is an older but not "Whoa, what are you thinking!?" graphics card running on an active miner, I produce about 0.01 BTC per day. At the current exchange rates, that's...about a dollar a day.