According to several sources (including leaks from those who attended the live auditions), we definitely have some familiar faces among those passed through to Boot Camp and many more among the applicants. Among those are believed to be:
Miss Permatragedy herself (meant with a long sigh), Angela Martin. Because Ellen couldn't make things any better either. Supposedly Simon personally invited her. Status unknown.
Clint Jun Gamboa. If the name doesn't ring any bells, think of the last season of AI. Then think of a praying mantis. Which couldn't sing. Reached the 24 and was promptly voted out. Made it through the audition phase anyway.
Stevie Wright. AI #8, semifinalist. Status unknown.
The Brittanum twins. Singing show regulars whether you want them to be or not. Status unknown.
Chris Golightly. AI #9, initially made the 24, but was disqualified at the last minute and replaced with Tim Urban. Status unknown.
Nathaniel Marshall. AI applicant. Rejected in Newark.
Add any other 3R candidates (reuse, recycle, reject) you find out about here.