==Reversion of edit==  
 "Looking for trouble"?  Hardly!    Simply attempting to improve the grammar on Wikipedia.  

 "Likely" is one of the rare adjectives that ends in "ly". The others are "lovely", "homely" and "comely".  I can't think of any more. However, you can see the historic connection between these words. 

 The sentence called for the use of an adverb, not an adjective. The two available adverbs are "probably" and "possibly".   

 If "likely" is going to be used then the sentence must read: "It is likely that......", in the same manner that one would write "It is probable that...." or "It is possible that....."  

 "Likely" equates to "possible" and "probable" as a part of speech. It doesn't equate to "probably" and "possibly".