I was just trying to work out the story on developing Metro Apps.
It looks like Metro Apps for Windows 8, Windows RT or Windows 8 phone can be distributed in two ways.
1. the Windows Store which needs a US$49 a year registration.
2. Side loading from Windows 8 Enterprise edition. This is the way corporate customers can install in-house metro apps on a Windows RT tablet. To get Windows 8 Enterprise, you need to sign up for Microsoft's "Software Assurance" which looks like a starting price of about $109 a year for one computer.
Windows RT and phone will only run Metro apps. All Metro software will need a certificate, but it is from any trusted authority - even your own in-house certificate server if you specify it as a trusted server to your companies Windows computers. This means for in-house company use, you do not have to spend any money for certificates.
For submitting to the Windows Store, I do not think you need to buy any certificates from Microsoft - another trusted certificate server is fine. If that is right, that would mean that there can be competition between providers, just as in the current SSL certificate marketplace.
If you need to develop a bootable application for the Intel based Windows 8 platforms that have a permanently enabled UEFI, you will need to pay Verisign $99 for a UEFI certificate. Every time you build a new version of the boot code, you need a new certificate. I gather the way Linux will handle this is to have a simple signed bootloader that hopefully hardly ever needs changing that then runs the Linux loader that will be regularly updated.
So it may be that Microsoft will not make all that much money from the process of developers getting Apps signed. They will make money from the Windows store - $30% for the first $25,000 of sales and reducing to 20% above this. There is also the $49 a year Windows Store subscription from developers. Aussies get the privilege of paying $55 a year because we love Microsoft so much. Microsoft will make money from corporations signing up to the Software Assurance scheme so that they can buy Windows 8 Enterprise that enables them to distribute Metro Apps in-house without using the Windows Store.
I am guessing that Microsoft will have the ability to tell all connected Windows Metro platforms to revoke a certificate of any rouge App, so in theory, a misbehaving app can be very quickly disabled for all users.
Is all of this a great solution? Probably not, but it seems to be the best working scheme for now. All current models of securing computers based around non-signed software and firewalls have been a massive failure. All current computer systems with no software signing are like houses with a magnificent heavily locked front door, but all the windows are left open.
Will signing cure the security problems, or will attackers keep finding just as many holes? I don't know.
Richard.