Well, you can think of bitcoin like about share of stock - cos their numbers is limited, if you believe in the future rise of bitcoin - you can mine even if current difficulty/price dont seems so good. And if you did not believe - you should not.
We've been over this a hundred times already.
If you're going to bank on the value of bitcoin rising in order to make your mining profitable, you're still doing it wrong.
If you really, truly believe that bitcoin value is going up: buy bitcoins directly and skip the hardware part. Don't like the risk? Spend half as much on bitcoins as you would on hardware.
The whole idea of relying on rising exchange rates to make your mining hardware profitable as opposed to buying directly is ludicrous, but won't go away.
Disclaimer: I don't believe bitcoin values will continue rising forever.