A combination of taps, straight lines and circles on a picture to unlock the phone.

If your device has a PIN requirement that will wipe the device after N failures (like when using Exchange), challenge the user intervene with something like the Windows Mobile style a1b2c3 or the exchange password before wiping the phone. The current system makes it super trivial for a child or pants-dial to inadvertantly wipe the contents of the phone.

Potentially private or sensitive discussion could be viewed by someone other than owner. At least give option to show or not.

to view or send text you need a password. to view or use pictures you need a password. to view contacts you need a password.

Picture password as an option.

Many enterprises requires NTLM authentication to access their Sharepoint deployments.

iOS provides this functionality.

Need to support installing and using self-signed and/or corporate certificates for ssl.

It would be great if there will be a privacy control system, locking some apps,picture album, other media contents etc to make them away-from-undesirable-viewers- showing-a-lock-icon-on-each-locked-tile-or-content-which-require-a-password-to-unlock.

A grid with all installed applications and all possible rights (location, data services, owner identity, etc.) to see in one place which rights are used by which application and help to easily manage your personnal data security.
This feature could be in settings->applications->overview

Appointment details and text messages are displayed, sometimes containing sensitive data. I would like an option to hide the messages and leave the icon only.

The ability to see and manage certificates installed on the phone also able to manage via Zune software.

The NFC functionality in WP8 is very nice, but the OS always asks for confirmation when you hover over a sticker.
I personally know what my own NFC stickers do, so I don't really need the confirmation, though I understand that you would want to know what a sticker does when you're somewhere else.

Wouldn't it be great if I could tick a checkbox to 'trust' a unique NFC sticker, so that you can remove the dialog after the first time? I think it would make NFC stickers 10 times more useful.

password/gesture protection for selected content like sms,gallery,image,webpage,mail account etc

Picture password, or some other type of pattern or swype password, for windows phone would be delightful. Would love to see this in a future update.

Use your face to unlock the phone.

I can control my daughter's online activity on her laptop through Windows Live Parental Controls; however, ***oon ***he's on her phone it's wide open. I'd really love for these LiveID ***ociated controls to extend to the phones.

How about porting the PC version of Microsoft Security Essentials & Windows Firewall to WP7. This will make the platform extra secure.

this phone should have a Mazelock app for screenlock