Emily is in love with Damian.
During her last confessional, she says she tried hard not to fall in love with her fellow competitors but did. Then she says she hopes there's a "pot of gold at the end of the rainbow." Leprechauns are usually the source of pots of gold near rainbows... Lea Michele will appear as a mentor twice.
Darren was the first mentor in Season 1, and appeared twice. Lea's the first mentor of season 2, and definitely the show's biggest star.- Jossed, Lea only appeared in that episode.
The show's format was poorly thought out and it took until the Season 1 finale for production to realize it.
The point of the show was to convince Ryan Murphy to write a role for them on Glee but the only time Ryan Murphy was face to face with the contestants was during last chance performances. Contestants not only got to sing live in front of him but tell a little about themselves and essentially build a rapport with Ryan Murphy. By the end of the competition, Ryan Murphy had a dilemma of should he reward the technically proficient Sam and Lindsey who rarely were ever up for elimination or give it to Alex and Damian who had terrible track records on paper but stood out as much more interesting in Ryan Murphy's eyes. Giving everyone a role might as well have been his way to circumvent the issue. The role for the season 2 winner was already written
Related to the above guess, as Ryan might interact with the contestants a little bit more but still not enough to get a good feel for them as people. It's very possible that he and the writers sketched out four characters concepts heading into Glee Project season 2 and Glee season 4 - a Loveable Jock, a Bad Boy, a MeanGirl, and an Ingenue. Then when Blake, Ali, and Aylin got to the finals he could slot whoever he picked into whichever one of those roles and allow the others to be cast normally. That way they can already plan out the season and the arcs without having to throw a wrench into things by figuring out why there's suddenly an Irishman or dreadlocked Christian involved with the club partway through production. It also might explain why Blake won out - he was so generic that he could slide into the role of Ryder pretty easily.