I’ve just received an email from Blizzard (from the same address that sent me the original alpha/beta invite), telling me the new installer is ready. Apparently you delete the existing game, then download a new one from battle.net.
Important note: as an Oceanic player, the battle.net URL redirected me to SEA.battle.net which gives a BROKEN downloader. Manually type in https://us.battle.net/ and download the beta installer from there instead, and it works. Thanks to the fellows on official forums.
Hopefully everyone will be careful here and only download from battle.net, and not from any clever phishing scammers.
I’m travelling with work Thur/Fri, so can’t install this til the weekend on both my Windows 7 and Mac clients. I hope they have optimised the download size, so it doesn’t require repeated patching after the initial install; ie. the initial version is very close to current beta version.
I checked the new installer, and it does not appear to be ready yet. Gives an error ‘download is not authorised’, which means the backend servers and maintenance aren’t all finished yet.