Just a short tip for everyone who needs access to betas without a developer account. The follow command brings back access to regular beta downloads via the AppStore!

Just replace the Catalog URL with:

sudo defaults write /Library/Preferences/com.apple.SoftwareUpdate CatalogURL https://swscan.apple.com/content/catalogs/others/index-10.10beta-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog.gz

Have fun!