A quick few points from my trip to the beach arcades [last holy refuge of the arcade in the US..I swear, also take ina ccount I haven't been ina decent arcade in a couple years since everyone close by has gone under):
-Guitar Hero Arcade is nowhere near as cool as the home version. Operators generally kept the machines in high traffic spots for them to garner attention, but it becomes troublesome because you often need the space to play. Not to mention they kept the machine's volume down so the surrounding din nearly always drowned it out.
-Has no one come up with a decent arcade racer in the last 5 years?
-Light gun shooters seem to be the dominate modern arcade game type.
-I was disappointed thatt he largest arcades in a resort town didn't have a SFIV machine. Hell, one did not have a single fighter at all.
-Skeeball still kicks ass.