Few minutes ago Apple has just released iTunes 10.5 Beta 5 with iTunes match for developers in the United States.
The beta requires the current iOS 5 beta and iTunes 10.5 beta 6.1 — and a paid subscription to iTunes Match, which runs $25 per year. However, the beta will also come with an additional three free months of the service. Additional notes from the release:
To get started with iTunes Match, download the current version of iOS 5 beta and iTunes 10.5 beta 6.1 with iTunes Match. Once installed, choose Turn On iTunes Match from the Store menu, and click “Subscribe for $24.99.”Please note that you must maintain a local backup of your iTunes library as well as any music you add to iCloud. Apple will periodically reset your iCloud library during the beta and it is critical that you backup your music regularly. Some features and optimizations of iTunes Match will not be available during the beta.
Download iTunes 10.6 beta 6.1 for Mac (Direct link)