Cyclops
Magneto
Emma Frost
Storm
Colossus
Iceman
Beast
The FF
Reed
Sue
Thing
J.Storm
The Defenders
Black Panther
Dr.Strange
Ghost Rider
Namor
Thunderbolts
Punisher
Rulk
Agent Venom
Deadpool
This is current Marvel..
This morning today the only heroes on Marvel Earth left are the teams above..
All current Marvel villians are still around on Marvel Earth..
Can the teams keep Earth safe or will they be over run by the villains in due time?
The heroes biggest advantage is that most of them already a decent working relationship. Villains tend to work solo and when they do work together they tend to be suspicious of one another, their egos don't really allow them to work together long term. The street levelers can work together okay, but the major threats, Dr Doom for example end up plotting against the villains they team with.
Yeah, they should be able to keep Earth safe. Of course, the big brains might create a nightmare scenario where its all controlled by robot policemen, but they'll keep it safe.