Later on Wednesday, we'll hear from the Fed's Janet Yellen after the FOMC's two-day meeting in Washington.  Key for Saxo Bank's Head of Macro Strategy, Mads Koefoed, is whether they change the wording on when we'll see higher interest rates in the States. Could the 'considerable time' phrase be changed to 'patience' on how long rates will stay low? 
Also to consider, the turmoil in the markets following the crash in the Russian ruble this week. This may mean the Fed will delay making any major market-making move until things calm a little.