much effort has already been put into creating a
thegamesdb scraper, albeit for a futuristic python-based scraper system called Heimdall created by topfs2.
A big problem with scraping games is guessing the platform. A couple months ago I started
PyRomInfo as a plugin for Heimdall. For most of the supported platforms (currently gb, gba, genesis, ms, nes, n64, snes) i was able to program in magic-word detection, so the platform can be guessed simply on the binary data alone. This will help for games with a .bin or .iso extension. With a scraper as smart as Heimdall, we start to approach a scenario where scanning is unnecessary; simply adding the source will be all that is needed to populate your entire library.
Speaking of thegamesdb, I noticed they are running a fundraiser. For the future of RetroPlayer and the XBMC games library, I hope they do well