Apple has released iTunes 10.5.1 beta 3 to developers which includes stability and performance improvements for iTunes Match. Developers must update to iTunes 10.5.1 beta 3 if they want to continue using the service.
The iTunes beta update comes hot on the heels of Apple deleting developer’s iTunes Match libraries again. All of these things should add up to a launch of iTunes Match sooner rather than later. Apple originally stated a released date of October but that has come and gone.