It's out.
XInput only - I have to use x360ce for my stick to work. Same problem that Calamity Trigger's PC port has.
Netcode is the same as PS3's, I believe.
Keyboard support is what's all fucked up. You're assigning buttons to act as a 360 controller. e.g. first you assign your J key to act as, say, left trigger. Then you hit J in controller options to set it to Punch or whatever and it'll tell you Punch is left trigger.
This gets REALLY screwy in 2P mode. IIRC I didn't see the all-important controller select so when I had my single controller plugged in I ended up choosing both 1P and 2P's characters.