Until ASICS come out, I find it hard to believe that miners are making reasonable profits. There must still be a surplus of bitcoins in the hands of early adopters and thieves keeping the price down. With the supply growth halving and interest growing, this should be corrected upward.
What's "reasonable"? The initial equipment costs certainly are there, but if you have a 7970 as an example, that will mine at roughly 600Mhash/s while using around 300W of power. You'll create roughly 0.16 BTC per day, which is worth $1.92 if you sell at $12. Your electricity costs will be around $0.72 ($0.10 / kWh). So, every day a single 7970 will earn about $1.20, which is $36 per month, all for doing basically nothing. Plus you get to offset the costs of heating your house in the winter (which is what I'm doing), which almost takes the electricity costs out of the equation. The catch of course is that you'd have to invest $400 for a 7970, which means one year to break even if everything stayed consistent. Then again, if you're a gamer and happen to have a 7970 already for that purpose, it's "free money" of a sort.
Six months ago the BTC rate from a 7970 was more like 0.35 BTC/day, but then the price was lower as well, so we're basically even. When the price broke into $10+ range and we were still at <2mil difficulty, profits might have approached $3/day/7970. Ultimately, though, I agree with you: mining and investing in mining equipment seems like a losing situation, if you have to pay for the hardware and can't sell it when you're done (or break it by stressing it too much). ASICs won't be much better unless you're in early -- and they come out sooner rather than later.
