After House of M most mutants lost their powers and unlike Iceman stayed that way. Here is a list of mutants that have been depowered. Most mutants on this list came from a variety of comics and Wizard #172. This might be a bit of a spoiler so just to make sure if you don't want to know, don't click on the link.
Click here to read the list of De-powerd Mutants.
Aardwolf (Wizard #172)
Aaronson, Christopher Terrance- King Bedlam (Wizard #172)
Adder, Puff- (Wizard #172)
Alleyne, David- Prodigy (New X-Men #20)
Anais (Wizard #172)
Argosy, Rachael- Rhapsody (Wizard #172)
Baer, Michael- Blockbuster (Wizard #172)
Barret, Sophia Mantega- Wind Dancer (House Of M #8)
Bermen, Adam- Primal (Wizard #172)
Bloodlust (Wizard #172)
Bohusk, Barnell- Beak (Exiles #72)
Boost (Wizard #172)
Bora (Wizard #172)
Brass (Wizard #172)
Briquette (Wizard #172)
Bugman (Wizard #172)
Callasantos, Lucia- Thornn (House Of M: The Day After)
Callasantos, Maria- Feral (House Of M: The Day After)
Callisto (Wizard #172)
Cassidy, Thomas Samuel Eamon- Black Tom (Wizard #172)
Christine ?- Angel Dust (Wizard #172)
Colbert, Marie-Ange- Tarot (Wizard #172)
Conquistador (Wizard #172)
Corbo, Adrian- Flex (Wizard #172)
Corbo, Jared- Radius (Wizard #172)
Cruz, Brian- Tag (House Of M #8)
Dane, Lorna- Polaris (X-Men #177)
Darby, Randall- Shocker (Wizard #172)
Dastoor, Aloba- Monsoon (Wizard #172)
David ?- Postman (Wizard #172)
Doc (Wizard #172)
Dragonwing (Wizard #172)
Dukes, Fred J.- The Blob (House Of M: The Day After)
Dzema (Wizard #172)
Falcones, Arturo- (Wizard #172)
Fatale (Wizard #172)
Flambe (Wizard #172)
Flubber (Wizard #172)
Freakshow (Wizard #172)
Garnoff, Alex- Blind Faith (Wizard #172)
Gazer (X-Men #177)
Geech (Wizard #172)
Gibney, Kyle- Wild Child (Wizard #172)
Gibson, Dallas- Specter (New X-Men #20)
Gill, Richard- Wildside (Wizard #172)
Gloom (Wizard #172)
Graves, Andrew Hamish- Spoor (Wizard #172)
Guan, Dai- Jade Dragon (Wizard #172)
Guthrie, Melody- Aero (New X-Men #20)
Hack (Wizard #172)
Hamilton, Patricia- Merwoman (Wizard #172)
Harsaw, Eileen- Phantazia (Wizard #172)
Hollis, Buford- Razorback (Wizard #172)
Hub (Wizard #172)
Hume, Colin Ashworth- Windshear (Wizard #172)
Hurageb, Pantu- Reaper (Wizard #172)
Inkose, Shola- (Wizard #172)
Kaiman (Wizard #172)
Kaufman, Daniel- (Wizard #172)
Kaufman, Lara- Lara the Illusionist (Mutopia X #5)
Key (Wizard #172)
Kivelki, Ivan- Black Death (Wizard #172)
Kiwi Black (Wizard #172)
Kleinstock, Harlan- (Wizard #172)
Kleinstock, Sven- (Wizard #172)
Labrov, Illyich- Sibercat (Wizard #172)
Lee, Jubilation- Jubilee (House Of M: The Day After)
Lehnseher, Eric Magnus- Magneto (House Of M #8)
Leevauld, Miranda - Stacy X (Generation M #2)
Levy, Hannah- (House Of M: The Day After)
Lightning Rod (Wizard #172)
Lilli ?- Ghost Girl (Wizard #172)
Lobo, Maximus (Wizard #172)
Longarms (Wizard #172)
Maddicks, Arthur- Artie (Wizard #172)
Marguilles, Andrea- Rubber Maid (Wizard #172)
Marks, James- Hybrid (Wizard #172)
Martin, Jeannie- (Wizard #172)
Mary ?- Mary Zero (Wizard #172)
Matsuya, Takeshi- Wiz Kid (Wizard #172)
Maximoff, Pietro- Quicksilver (House Of M: The Day After)
Maximoff, Wanda- The Scarlet Witch (Wizard #172)
Mesmero (X-Men Unlimited #13)
Mist Mistress (Wizard #172)
Montoya, Alejandro- El Aguila (Wizard #172)
Moonstar, Danielle- Mirage (House Of M: The Day After)
Neo (Wizard #172)
Neophyte (Wizard #172)
Nightwind (Wizard)
Noatak, Kodiak- Harpoon (Wizard #172)
Nord, Christopher David- Maverick (Wizard #172)
Ortega, Armena- (Mutopia X #5)
Overrider (Wizard #172)
Patterson, Paul- (Wizard #172)
Peterson, Gary- (Wizard #172)
Purge III (Wizard #172)
Purge IV (Wizard #172)
Radian (Wizard #172)
Rain Boy (Wizard #172)
Rendoza, Hector- Wraith II (Wizard #172)
Reuben ?- Tantra (Wizard #172)
Richter, Julio Esteban- Rictor (X-Factor #1)
Roid (Wizard #172)
Romeo, Tony- (Wizard #172)
Rust (Wizard #172)
Ryking, Carter Alexander- Hazard (Wizard #172)
Salomon, Aaron- Slither (Wizard #172)
Salvatore, Angel- Angel IV (Exiles #72)
Sarah ?- Marrow (Wizard #172)
Scanner (Wizard #172)
Shatter (Wizard #172)
Sheppard, Mark- DJ (Wizard #172)
Silicon (Wizard #172)
Skein (Wizard #172)
Sky-Walker (Wizard #172)
Slick (Wizard #172)
Slik, Mickey- Poltergeist (Wizard #172)
Spector, John- (Wizard #172)
Spike III (Wizard #172)
Spoilsport (Wizard #172)
Starsmore, Jonathan- Chamber (Generation M #1)
Strobe (Wizard #172)
Styger, Nils- Abyss (Wizard #172)
Tatoo (Wizard #172)
Tether (Wizard #172)
Toad-In-Waiting (Wizard #172)
Tough Love (Wizard #172)
Tremalo (Wizard #172)
Truffaut, Arlette- Murmur (Wizard #172)
Ugly Guy (Wizard #172)
Uniscone, Angelo- Unus (Wizard #172)
Vague (Wizard #172)
Vale, Jessica- Preview (Wizard #172)
Wall (Wizard #172)
Warbeck, Davis Cameron- Slipstream (Wizard #172)
Wicked (Wizard #172)
Worthington III, Warren- Angel/ Archangel (Generation M #4)
Xavier, Professor Charles- Professor X (Wizard #172)
Xorn, Shen- Xorn II (Wizard #172)
Yashida, Shiro- Sunfire (Wizard #172)
Zach ? (Wizard #172)
This list was compiled by Rich Rank. Thanks for your help Rich!