[quote=@Pirouette]So. Are new apps limited to this selection? 
[/quote]
Nope, new apps can be any character currently not indicated on the roster. For ease of reference here's the current roster:

[quote=@Master Bruce][CENTER][color=656565][b]Batman / Bruce Wayne[/b][/color]
Master Bruce

[b][color=820893]Black Panther / T'Challa[/color][/b]
Star Lord

[b][color=7ea7d8]Blue Beetle / Jaime Reyes[/color][/b]
Superboy

[color=0054a6][b]Captain America / Steve Rogers[/b][/color]
Eddie Brock

[b][color=fff79a]Doctor Fate / Kent Nelson[/color][/b]
Korack

[b][color=ff9900]The Flash / Iris West[/color][/b]
Sep

[b]Heroes For Hire
Adrian Chase / Misty Knight[/b]
Byrd Man

[b][color=8C73B5]The Huntress / Helena Bertinelli[/color][/b]
Inkarnate

[b][color=fff200]Iron Fist / Daniel Rand[/color][/b]
webboysurf

[b][color=Green]Martian Manhunter / J'onn J'onnz[/color][/b]
Hillan

[b]Moon Knight / Marc Spector[/b]
Hound55

[b][color=skyblue]Mordred Pendragon[/color][/b]
Bounce

[b][color=fff200]Ms. Marvel / Carol Danvers[/color][/b]
IceHeart

[color=black][b]The Punisher / Frank Castle / Fang Chu[/b][/color]
Simple Unicycle

[b][color=cornflowerblue]Reed Richards[/color] / [color=paleturquoise]Susan Storm[/color] / [color=firebrick]Johnny Storm[/color] / [color=darkorange]Ben Grimm[/color][/b]
Morden Man

[color=deeppink][b]Spider-Woman / Gwen Stacy[/b][/color]
HenryJonesJr

[color=RoyalBlue][b]Superman / Clark Kent[/b][/color]
AndyC

[COLOR=GOLDENROD][b]King Thor / Blake Donaldson[/b][/color] 
Lord Wraith

[color=#f92a0e][b]Vigilante / Greg Saunders / The Spirit Of Vengeance[/b][/color]
DocTachyon
[/CENTER]

[/quote]

Here's the character sheet template if you missed it.

[quote=@Master Bruce][hider=New Character Sheet][u][b]Ultimate One Universe: Season Two Application[/b][/u]

[b]Character You're Applying For:[/b] 

[b]Powers And Abilities:[/b]

[b]Origin And Backstory (In A Maximum Of Four Paragraphs):[/b] 

[b]What Makes This Character 'Ultimate'?:[/b]

[b]Supporting Characters:[/b]

[b]Character Picture:[/b]

[b]Sample Post:[/b][/hider]
[/quote]