Apple is no longer restricting Mac OS X betas to paying developers. Anyone with an Apple ID (which is, let’s face it, essentially every Apple user at this point) can now sign up for the OS X Beta Seed Program to test unreleased versions of the operating system. You have to agree to Apple’s OS X Beta Seed and Confidentiality Agreement and install the Beta Access Utility to view betas in the Mac App Store. After WWDC, we’ll see if this applies to major releases of OS X, or just minor updates.follow link
Improve Apple Services with AirPort Base Stations
You can make iChat file transfers, iDisk, and Back to My Mac work better by turning on a setting with Apple AirPort base stations released starting in 2003. Launch AirPort Utility, select your base station, click Manual Setup, choose the Internet view, and click the NAT tab. Check the Enable NAT Port Mapping Protocol (NAT-PMP) box, and click Update. NAT-PMP lets your Mac OS X computer give Apple information to connect back into a network that's otherwise unreachable from the rest of the Internet. This speeds updates and makes connections work better for services run by Apple.
Apple Opens Mac OS X Betas to All