

On March 5, 2010, the Bureau of Engraving and Printing announced that the new $100 bill design would be unveiled at an April 21, 2010, event.[4]
The new bill will receive design changes analogous to the current $5, $10, $20 and $50 bills.[5] Originally, the new $100 bill had been expected to be announced in late 2008, however, the Federal Reserve’s 2009 budget data anticipated the official presentation taking place at the end of 2009 or first quarter of 2010.[6]
Although the redesign has been publicized as routine, the sophisticated “Superdollar” is a major concern.[7] The new bills will contain a Crane & Co. security feature called Motion, containing up to 650,000 microlenses embedded in the printing which will allow for an underlying image to shift when the bill is moved.
source : en.wikipedia.org