Under normal circumstances, no, it's barely usable and is wildly outclassed by Ice Beam, Freeze Dry and Hidden Power Ice. Those moves should always be considered before looking at Icy Wind.
However, if you are playing doubles, Icy a Wind is much more usable than it is in ordinary singles. The 100% Speed drop is invaluable in a metagame that isn't switching so much, and it allows Pokemon like Cresselia to elevate its low Speed. It's a great support move with great distribution which should always be considered on teams lacking Trick Room or Tailwind.
Source: Been using it successfully for months.