GPU mining is going to be non-effectives now that asics are being rolled out. Though the new nividias look pretty sweet 
This is relative and it depends on the BTC price. right now, if you have three 7970's you would be mining about 3BTC/Month, that's U$S390 at current prices, and if you have decent cheap electricity or free electricity then you're definitely making profits.
I pay $27 dollars per rig for my electric bill, and I'm mining about 6BTC/month so that's almost $800 minus $60 for electricity...
That's pretty good....
Also it doesn't matter how many coins you mine, but the price of the coins. If you mine 1 coin a month in 6 months, but BTC prices are $400-$600 then you're still making decent money...
like you could get much more profit with ltc
just saying bro