JUST TO SUMMARIZE (by age) what we have so far:
Dan McMillen. 21. College Student. Liberty, Missouri. Sam McMillen (Brother)
Matt Tomljenovich. 22. Mortgage Broker. Billings, Montana. Gary Tomljenovich (Father)
Mika Combs. 22. Country Musician. Nashville, Tennessee. Canaan Smith (Dating?)
Sam McMillen. 23. College Student. Liberty, Missouri. Dan McMillen (Brother)
Meghan Rickey. 23. Account Executive. San Diego, California. Cheyne Whitney (Dating)
Cheyne Whitney. 24. Social Change Mentor. San Diego, California. Meghan Rickey (Dating)
Tiffany Michelle . 25. Professional Poker Player. Los Angeles, California. Maria Ho (Friend)
Canaan Smith. 26. Country Musician. Nashville, Tennessee. Mika Combs (Dating?)
Maria Ho. 26. Professional Poker Player. Los Angeles, California. Tiffany Michelle (Friend)
Zev Glassenberg. 26. Actor. Los Angeles, California. Justin Kanew (Friend?)
Jessica Stout. 27. Editor. San Francisco, California. Unknown Partner (Dating/Engaged?)
Ericka Dunlap. 27. Pageant Queen / Singer. Nashville, Tennessee. Brian Kleinschmidt (Married)
Brian Kleinschmidt. 27. Actor / Marketing Director. Nashville, Tennessee. Ericka Dunlap (Married)
Nate Lofton. 28. NBA Player. New Orleans, Louisiana. Herbert Lang (Friend/Teammate)
Justin Kanew. 30. Actor/Writer/Producer. Los Angeles, California. Zev Glassenberg (Friend?)
Herbert Lang. 33. NBA Player. Shreveport, Louisiana. Nate Lofton (Friend/Teammate)
Keri Morrione. 34. Hospital Manager. Everett, Massachusetts. Lance Layne (Engaged)
Lance Layne. 41. Attorney. Salem, Massachusetts. Keri Morrione (Engaged)
Gary Tomljenovich. 47. Mortgage Broker. Billings, Montana. Matt Tomljenovich (Son)
Ron Shalita. 59. SAT Preparation. San Francisco, California. Marcia Maloy (Dating)
Marcia "Marcy" Wynkoop. 60. Photographer. San Francisco, California. Ron Shalita (Dating)
That leaves ONLY Jessica's partner and the mystery twelfth team.
ETA: I find it really interesting to notice the significant difference between this cast and last season's.
Season 14 had 10 in the 20s and 12 over 35. This season has at least 15 in the 20s (assuming Jessica's partner is not over 30), and currently only 4 over 35.
ETA: Ron is Marcia's partner.