nvm, its fixed now, i can finally logged in, phew.

i deleted cache, still giving me

Oops, unknown username or password. If you are logging in with a Mojang account make sure to use your e-mail address as username.

i used right email and password, i also scan virus says no keylogged...

Servers seem fine could change my skin, maybe try a different browser or delete your cache?

i can login just fine since yesterday till today i cant even login, to change skin but im able to play singleplayer and multiplayer server, usually it gives me error message if im hacked ( that happened to my friend ) but i dont get any error message when i login ingame world map.

mojang is not down

none of those worked, i already contract with mojang, i hope it just bugged with 1.7 bugs...unless someone able to login just fine, looks like im gonna play singleplayer with new 1.7 for little.

I'm having similar trouble, but only on a specific computer. with me it says that it can't connect to the minecraft login servers, while the servers and my internet connection are fine.

I suggest you try the following things:
use your previous password (the change may not have registered for some reason)
try to login using your former username (while the mojang account thing generally works, it is a relatively new feature and might still have some bugs)
try logging into minecraft on a friend's computer, or at least a different computer
try a different network
if the above doesn't work, try resetting your account.
if that doesn't work, contact mojang directly, as it is their responsibility if an account doesnt work.

That's all I can give you.

If you wanna check if mojang server are down, use http://minecraft.goldencreate.com/mcstats.php