As we said back in April 2010, "Call us nerds if you like, but the classic 70's and 80's arcade games are a heritage worth preserving, a record of the origins of today's games that needs to be preserved for future generations". By far the most complete code framework for the preservation of that gaming heritage is MAME (Multi Arcade Machine Emulator). Until now MAME has only been available to those with jailbroken iPads. Today that changed.
However, so far it appears that there is no way of side-loading arcade ROMS, hence you are limited to testing the arcade hardware emulation with the 10 basic games that come preinstalled. But how long will it be until some bright spark finds a way to side load more games, and how long after that event will it be until Apple removes iMAME from the App Store? Looking through the iMAME menu items it seems clear to us that this app is a fully featured version of MAME.
What are you doing still reading this? Get iMAME while you still can, the clock is ticking people!
Source: Touch Arcade - The best source for iPad gaming news and reviews.
App Store Link: iMAME (Free)
Further Reading: Games
The Touch Arcade article now includes an update that shows how to side-load ROMS. This app will not be in the store for long folks!
iMAME also seems to work with iCade, and certainly supports TV output at 720p via cable or Apple TV.
Response: ev oyunlarıiPad Creative - iPad Creative - iMAME, the iPad arcade finally arrives!