as far as the world scene goes, quigg is definitely just a prospect. i'd only consider him a contender at domestic level seeing as you have jason booth and rendall munroe as the current british top 2 in that weight class.
Ioka's had 6 pro fights. He may have lined up an undeserving title shot, but he's still a prospect until the fight happens. I expect him to beat Sithsamerchai, actually, unless draining all the way to 105 has a bad effect on him.
IMO contending for a title makes you a contender, the same applied to Shumenov, and Chisora now as well.
Im surprised nobodys mentioned Keith Thurman yet. hes one of the most underrated prospects around and i see him moving up a level this year.