Profitability of mining scrypt has dropped considerably from where it was in early to mid December, however, as long as you have cheap (or free) power, you'll probably make ROI within a few months.

Of course, with the variability of the markets, profit changes day by day, however, in my opinion, investing in hardware still isn't a bad deal, as the components still have a value in their utility to others (for gaming/rendering/etc) even IF scrypt mining was no longer profitable.

That said, know that the price of the hardware would probably drop by 35-50% or so if that were to occur... 7950's were going for around $180-200 as recent as early November... and 280x's are only supposed to retail for $300 new (not counting ones with custom cooling solutions)

Just remember to set aside money for your power bill if you do invest in hardware :p Nothing like waking up and realizing (even at $0.085 per KW/h) you owe $450 haha