Wow I take like a decade off and everything is different.
Mame is way different from version 56.
does anyone even do game pad hacks any more?
Definitely lots of changes. The Zero Delay Encoders can be found on ebay and have taken the place of Mame gamepad hacks for most folks.
Big front end changes: check out Hyperspin, MALA and who knows what others - those are just the main two I use
Lots of kits available - Bartops especially made a big splash
In the commercial world, lots of retro offerings from working keychain games to full size replica rebuilds
AIMTRAK is probably your best choice for shooting games
The games we are playing are mostly the same though.